function allineaLayer() {
  var myWidth = 0, myHeight = 0;
  if( typeof( window.innerWidth ) == 'number' ) {

    myWidth = window.innerWidth;
    myHeight = window.innerHeight;
  } else if( document.documentElement &&
      ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {

    myWidth = document.documentElement.clientWidth;
    myHeight = document.documentElement.clientHeight;
  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {

    myWidth = document.body.offsetWidth;
    myHeight = document.body.offsetHeight;
	}
			
	var x1;
	var x1=document.getElementById('layer1').style;
 	x1.left= ''+ (myWidth/2)-160 +'px';
}