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)
 {
reserve = newImage("img/reserve_over.png");
what = newImage("img/how_restaurant_what_over.jpg");
where = newImage("img/how_restaurant_where_over.jpg");
who = newImage("img/how_restaurant_who_over.jpg");
why = newImage("img/how_restaurant_why_over.jpg");

 preloadFlag = true;
 }
}