navegador = navigator.appName;
var navVer = parseInt(navigator.appVersion);

if (navegador == "Microsoft Internet Explorer") {
document.write("<LINK href='http://www.ruv.itesm.mx/portal/apps/css/winstyles.css' rel='stylesheet' type='text/css'>");
}

if (navegador == "Netscape") {
  if(navVer==4)
  {
   document.write("<LINK href='http://www.ruv.itesm.mx/portal/apps/css/winstylesns4.css' rel='stylesheet' type='text/css'>");
  }
  else
  {
   document.write("<LINK href='http://www.ruv.itesm.mx/portal/apps/css/winstylesns.css' rel='stylesheet' type='text/css'>");
  }
}

function escribeTop(){
document.write("<table width=\"775\" height=\"82\" border=\"0\" align=\"center\" cellpadding=\"0\" cellspacing=\"0\" background=\"http://www.ruv.itesm.mx/portal/imagenes/home/header/barra_imagen.jpg\">");
document.write("      <tr>");
document.write("        <td><table width=\"775\" height=\"82\" border=\"0\" cellpadding=\"0\" cellspacing=\"0\" background=\"some.gif\">");
document.write("            <tr>");
document.write("              <td width=\"161\" rowspan=\"2\" valign=\"middle\"><div align=\"center\"><span class=\"contentmenua\"><a href=\"http://www.sistema.itesm.mx\" target=\"_blank\"><img src=\"http://www.ruv.itesm.mx/portal/imagenes/home/header/logo_tec_monterrey.gif\" alt=\"Tecnol&oacute;gico de Monterrey\" width=\"127\" height=\"54\" border=\"0\"></a></span></div></td>");
document.write("              <td width=\"450\" height=\"80\"  rowspan=\"2\">&nbsp;</td>");
document.write("              <td width=\"149\">&nbsp;</td>");
document.write("              <td width=\"15\" rowspan=\"2\">&nbsp;</td>");
document.write("            </tr>");
document.write("            <tr>");
document.write("              <td valign=\"top\"><a href=\"http://www.ruv.itesm.mx\"><img src=\"http://www.ruv.itesm.mx/portal/imagenes/home/header/logo_universidad_virtual.gif\" alt=\"Universidad Virtual\" width=\"154\" height=\"13\" border=\"0\" usemap=\"#Map2Map\"></a></td>");
document.write("            </tr>");
document.write("        </table></td>");
document.write("      </tr>");
document.write("    </table>");
document.write("    <table width=\"775\" border=\"0\" align=\"center\" cellpadding=\"0\" cellspacing=\"0\">");
document.write("      <tr>");
document.write("        <td colspan=\"4\"><img src=\"http://www.ruv.itesm.mx/portal/imagenes/home/header/barra_delgada.jpg\" width=\"775\" height=\"10\"></td>");
document.write("      </tr>");
document.write("    </table>");

}