img1 = new Image();
img2 = new Image();
img3 = new Image();
img4 = new Image();
img5 = new Image();
img6 = new Image();
img7 = new Image();
img1.src = "images/nav_home_over.gif";
img2.src = "images/nav_company_over.gif";
img3.src = "images/nav_service_support_over.gif";
img4.src = "images/nav_career_opportunities_over.gif";
img5.src = "images/nav_contact_us_over.gif";
img6.src = "images/button_home_owners_over.gif";
img7.src = "images/button_architects_over.gif";

function imageRollOver(id) {
	document.getElementById(id).src = 'images/'+id+'_over.gif';
}
function imageRollOff(id) {
	document.getElementById(id).src = 'images/'+id+'.gif';
}