ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false

function imgChange(imgNam,imgSrc) {
document.images[imgNam].src = imgSrc;
}

function contactPop() {
window.open("contact_us.html", 'popup', "width=420,height=450,toolbar=0,location=0,directories=0, status=0,menubar=no,scrollbars=0,resizable=0").focus()
}