Most of the errors are syntax errors. You are using a XHTML 1.0 Transitional doctype. Errors like "onMouseover" are because it must be "onmouseover"...all lowercase. Other "errors" are like not closing tags which normally do not have closing tags with a space and a " / ". Adding a breal after the <ul> tag is not allowed. Some problems with missing closing tags. More are about the ampersand ( & ). It must be coded using its character entity in all html documents.
Result: 137 errors / 6 warnings
line 81 column 31 - Error: there is no attribute "onLoad"
line 85 column 76 - Error: there is no attribute "height"
line 87 column 145 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 87 column 14 - Info: start tag was here
line 88 column 98 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 88 column 94 - Info: start tag was here
line 92 column 16 - Error: character data is not allowed here
line 92 column 101 - Error: there is no attribute "alt"
line 95 column 54 - Error: required attribute "type" not specified
line 140 column 24 - Error: end tag for element "align" which is not open
line 140 column 29 - Error: end tag for "div" omitted, but OMITTAG NO was specified
line 95 column 10 - Info: start tag was here
line 143 column 30 - Error: document type does not allow element "div" here; missing one of "th", "td" start-tag
line 143 column 70 - Error: there is no attribute "background"
line 143 column 125 - Error: document type does not allow element "td" here
line 144 column 94 - Error: there is no attribute "onClick"
line 144 column 148 - Error: there is no attribute "onMouseOver"
line 144 column 245 - Error: there is no attribute "onMouseOut"
line 144 column 383 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 144 column 265 - Info: start tag was here
line 145 column 417 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 145 column 291 - Info: start tag was here
line 146 column 417 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 146 column 291 - Info: start tag was here
line 147 column 417 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 147 column 291 - Info: start tag was here
line 148 column 417 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 148 column 291 - Info: start tag was here
line 149 column 418 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 149 column 290 - Info: start tag was here
line 150 column 408 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 150 column 282 - Info: start tag was here
line 151 column 406 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 151 column 281 - Info: start tag was here
line 152 column 400 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 152 column 278 - Info: start tag was here
line 153 column 22 - Error: end tag for "table" omitted, but OMITTAG NO was specified
line 143 column 126 - Info: start tag was here
line 153 column 22 - Error: end tag for "td" omitted, but OMITTAG NO was specified
line 143 column 31 - Info: start tag was here
line 155 column 17 - Error: "tr" not finished but containing element ended
line 155 column 17 - Error: end tag for "tr" omitted, but OMITTAG NO was specified
line 142 column 8 - Info: start tag was here
line 156 column 14 - Error: end tag for element "td" which is not open
line 157 column 12 - Error: end tag for element "tr" which is not open
line 158 column 17 - Error: end tag for element "table" which is not open
line 163 column 10 - Error: document type does not allow element "br" here; assuming missing "li" start-tag
line 163 column 11 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 163 column 7 - Info: start tag was here
line 164 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 165 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 166 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 167 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 168 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 169 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 170 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 171 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 172 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 173 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 174 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 175 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 176 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 177 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 178 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 178 column 92 - Error: end tag for "li" omitted, but OMITTAG NO was specified
line 163 column 7 - Info: start tag was here
line 182 column 14 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 182 column 10 - Info: start tag was here
line 182 column 34 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 182 column 30 - Info: start tag was here
line 183 column 45 - Error: there is no attribute "onChange"
line 185 column 25 - Error: "SELECTED" is not a member of a group specified for any attribute
line 208 column 74 - Warning: cannot generate system identifier for general entity "B"
line 208 column 74 - Error: general entity "B" not defined and no default entity
line 208 column 75 - Error: reference to entity "B" for which no system identifier could be generated
line 208 column 73 - Info: entity was defined here
line 209 column 73 - Warning: cannot generate system identifier for general entity "M"
line 209 column 73 - Error: general entity "M" not defined and no default entity
line 209 column 74 - Error: reference to entity "M" for which no system identifier could be generated
line 209 column 72 - Info: entity was defined here
line 228 column 74 - Warning: cannot generate system identifier for general entity "L"
line 228 column 74 - Error: general entity "L" not defined and no default entity
line 228 column 75 - Error: reference to entity "L" for which no system identifier could be generated
line 228 column 73 - Info: entity was defined here
line 251 - Error: character data is not allowed here
line 251 column 86 - Error: end tag for element "option" which is not open
line 268 column 73 - Warning: cannot generate system identifier for general entity "R"
line 268 column 73 - Error: general entity "R" not defined and no default entity
line 268 column 74 - Error: reference to entity "R" for which no system identifier could be generated
line 268 column 72 - Info: entity was defined here
line 281 column 75 - Error: reference to entity "M" for which no system identifier could be generated
line 209 column 72 - Info: entity was defined here
line 286 column 73 - Warning: cannot generate system identifier for general entity "N"
line 286 column 73 - Error: general entity "N" not defined and no default entity
line 286 column 74 - Error: reference to entity "N" for which no system identifier could be generated
line 286 column 72 - Info: entity was defined here
line 295 column 75 - Error: reference to entity "M" for which no system identifier could be generated
line 209 column 72 - Info: entity was defined here
line 297 column 74 - Warning: cannot generate system identifier for general entity "H"
line 297 column 74 - Error: general entity "H" not defined and no default entity
line 297 column 75 - Error: reference to entity "H" for which no system identifier could be generated
line 297 column 73 - Info: entity was defined here
line 397 column 16 - Error: end tag for element "p" which is not open
line 398 column 10 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 398 column 6 - Info: start tag was here
line 399 column 21 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 399 column 17 - Info: start tag was here
line 401 column 114 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 401 column 110 - Info: start tag was here
line 403 column 15 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 403 column 11 - Info: start tag was here
line 405 column 11 - Error: ID "sectionLinks" already defined
line 162 column 11 - Info: ID "sectionLinks" first defined here
line 417 column 205 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 417 column 79 - Info: start tag was here
line 417 column 213 - Error: end tag for "center" omitted, but OMITTAG NO was specified
line 417 - Info: start tag was here
line 422 column 2 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 422 column 43 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 422 column 39 - Info: start tag was here
line 422 column 681 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 422 column 688 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 422 column 679 - Info: start tag was here
line 424 column 6 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 424 column 48 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 424 column 44 - Info: start tag was here
line 424 column 701 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 424 column 708 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 424 column 699 - Info: start tag was here
line 426 column 6 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 426 column 51 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 426 column 47 - Info: start tag was here
line 426 column 357 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 426 column 360 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 428 column 21 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 429 column 2 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 430 column 2 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 431 column 105 - Error: required attribute "alt" not specified
line 431 column 109 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 431 - Info: start tag was here
line 431 column 114 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 431 column 110 - Info: start tag was here
line 432 column 21 - Error: end tag for "b" omitted, but OMITTAG NO was specified
line 430 column 3 - Info: start tag was here
line 433 column 2 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 434 column 98 - Error: required attribute "alt" not specified
line 434 column 102 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 434 - Info: start tag was here
line 434 column 107 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 434 column 103 - Info: start tag was here
line 436 column 2 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 437 column 99 - Error: required attribute "alt" not specified
line 437 column 103 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 437 - Info: start tag was here
line 437 column 108 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 437 column 104 - Info: start tag was here
line 439 column 21 - Error: document type does not allow element "p" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 428 column 4 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 426 column 358 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 426 column 355 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 426 column 4 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 424 column 4 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 422 - Info: start tag was here
line 439 column 31 - Error: end tag for "p" omitted, but OMITTAG NO was specified
line 421 - Info: start tag was here
line 442 column 11 - Error: ID "sectionLinks" already defined
line 162 column 11 - Info: ID "sectionLinks" first defined here
line 443 column 11 - Error: document type does not allow element "br" here; assuming missing "li" start-tag
line 443 column 12 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 443 column 8 - Info: start tag was here
line 444 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 445 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 446 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 447 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 448 column 6 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 449 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 450 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 451 column 9 - Error: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag
line 452 column 8 - Error: end tag for "li" omitted, but OMITTAG NO was specified
line 443 column 8 - Info: start tag was here
line 455 column 22 - Error: value of attribute "method" cannot be "POST"; must be one of "get", "post"
line 457 column 72 - Error: there is no attribute "bordercolor"
line 460 column 88 - Error: end tag for "center" omitted, but OMITTAG NO was specified
line 460 column 12 - Info: start tag was here
line 464 column 82 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 464 column 78 - Info: start tag was here
line 465 column 83 - Error: end tag for "input" omitted, but OMITTAG NO was specified
line 465 column 12 - Info: start tag was here
line 465 column 83 - Error: end tag for "center" omitted, but OMITTAG NO was specified
line 464 column 12 - Info: start tag was here
line 470 column 76 - Error: end tag for "input" omitted, but OMITTAG NO was specified
line 470 column 6 - Info: start tag was here
line 470 column 76 - Error: end tag for "center" omitted, but OMITTAG NO was specified
line 469 column 12 - Info: start tag was here
line 475 column 8 - Error: end tag for element "td" which is not open
line 475 column 13 - Error: end tag for element "tr" which is not open
line 476 column 3 - Error: document type does not allow element "tr" here; assuming missing "table" start-tag
line 477 column 151 - Error: end tag for "img" omitted, but OMITTAG NO was specified
line 477 column 2 - Info: start tag was here
line 482 column 354 - Error: end tag for "br" omitted, but OMITTAG NO was specified
line 482 column 350 - Info: start tag was here
Line numbers refer to my editor, but might match yours. They match the validators for my pages. Just 2 CSS errors which should also be corrected.