function getBrowserHeight(){
if (window.innerHeight){return window.innerHeight;}
else if (document.documentElement && document.documentElement.clientHeight != 0){return document.documentElement.clientHeight;}
else if (document.body){return document.body.clientHeight;}
return 0;
}
function addEvent( obj, type, fn ){
if (obj.addEventListener){ obj.addEventListener( type, fn, false );}
else if (obj.attachEvent){
  obj["e"+type+fn] = fn;obj[type+fn] = function(){ obj["e"+type+fn]( window.event );}
  obj.attachEvent( "on"+type, obj[type+fn] );}
}

//addEvent(window, 'load', changeCenter);
//addEvent(window, 'resize', changeCenter);