function showAll(){
var myInner;
var minHeight = 500;
//die sichtbare fläche
(!ie)?px='px':px='';
(!ie)?myInner=window.innerHeight:myInner=document.documentElement.clientHeight;


    //verschiebt die gesamtseite
if (myInner>minHeight){
    var sub;
    (!ie)?sub=160:sub=220;
	document.getElementById("center").style.height=(myInner-sub)+px;
}
}

var browser=navigator.userAgent.toLowerCase();
ie = (browser.indexOf('msie')>-1);
window.onresize=showAll;