function imgOn(imgName)
{if (document.images) {document[imgName].src=eval(imgName+"on.src");}}

function imgOff(imgName)
{if (document.images) {document[imgName].src=eval(imgName+"off.src");}}

if (document.images)
{
imgg1on=new Image(); imgg1on.src="img/nav_work_over.gif";
imgg1off=new Image(); imgg1off.src="img/nav_work_off.gif";

imgg2on=new Image(); imgg2on.src="img/nav_info_over.gif";
imgg2off=new Image(); imgg2off.src="img/nav_info_off.gif";

imgg3on=new Image(); imgg3on.src="img/nav_contact_over.gif";
imgg3off=new Image(); imgg3off.src="img/nav_contact_off.gif";

}