function topnavlast(onoff) {
    var obj = document.getElementById("nav_end");
    if (onoff == 1) {
        obj.src = "/images/nav_right_end_on-trans.png";
    } else {
        obj.src = "/images/nav_right_end-trans.png";
    }
}
function changePhoto(imgsrc) {
	document.getElementById('productphoto').src = imgsrc;
}
function validateForm(form) {
  if (form.color.value == "") {
    alert("Please select a color.");
    form.color.focus();
    return false ;
  }
  if (form.size.value == "") {
    alert("Please select a size.");
    form.size.focus();
    return false ;
  }
	return true;
}