var image_name = null
if(document.images){

//icon1

icon1			= new Image();
icon1.src		= "img_icons/icon1.jpg";
icon1_over		= new Image();
icon1_over.src		= "img_icons/icon1_over.jpg";


//icon2

icon2			= new Image();
icon2.src		= "img_icons/icon2.jpg";
icon2_over		= new Image();
icon2_over.src		= "img_icons/icon2_over.jpg";


}

function change_over(image_name)
{
if (document.images){

if (image_name == "icon1") document[image_name].src = icon1_over.src ;
if (image_name == "icon2") document[image_name].src = icon2_over.src ;


}
}

function change_back(image_name)
{
if (document.images){

if (image_name == "icon1") document[image_name].src = icon1.src ;
if (image_name == "icon2") document[image_name].src = icon2.src ;

}
}