function newImage( imgSrc ){

 var imgName = new Image();
 imgName.src = imgSrc;

 return imgName;

}

function change( imgName, imgLocation )
{
 document[imgName].src = imgLocation ;
}

var preloadFlag = false;
function loadImages()
{
 if (document.images)
 {

var sobre = newImage("web/img/nav_top/tn_1_over_es.jpg");
var conozca = newImage("web/img/nav_top/tn_2_over_es.jpg");
var actualidad = newImage("web/img/nav_top/tn_3_over_es.jpg");
var eventos = newImage("web/img/nav_top/tn_4_over_es.jpg");
var recursos = newImage("web/img/nav_top/tn_5_over_es.jpg");
var pub_soft = newImage("web/img/nav_top/tn_6_over_es.jpg");
var formacion = newImage("web/img/nav_top/tn_7_over_es.jpg");
var anuncios = newImage("web/img/nav_top/tn_8_over_es.jpg");
var enlaces = newImage("web/img/nav_top/tn_9_over_es.jpg");



  preloadFlag = true;

 }
}