function centerpos(){
if(!window.innerWidth){if(!(document.documentElement.clientWidth == 0)){var w = document.documentElement.clientWidth;}else{var w = document.body.clientWidth;}}else{var w = window.innerWidth;}
var cw=document.getElementById('layer1').offsetWidth.toString();
document.getElementById('layer1').style.left=((w-cw)/2)+leftvar;
}