function navigation_background(obj, type, linknumber){
if(type == 1){
 obj.style.background = '';
 document.getElementById("links" + linknumber + "").style.color = '#FFFFFF';
 }
 if(type == 2){
 obj.style.background ="url(template/menuover.png)";
 document.getElementById("links" + linknumber + "").style.color = '#000000';
 }
}