function showback(){
	var height = document.compatMode=='CSS1Compat' && !window.opera?document.documentElement.clientHeight:document.body.clientHeight;
	var normheight = 657;	
	if(height>normheight)
		{
		document.getElementById("mainbg").style.height = height+'px';
		document.getElementById("main").style.height = height+'px';
		document.getElementById("shadow").style.height = height+'px';
		document.getElementById("mainbbg").style.height = height+'px';		
		document.getElementById("shdw_bg").style.height = (height-480)+'px';
		//alert(height);
		}
	else{
		document.getElementById("mainbg").style.height = normheight+'px';
		document.getElementById("main").style.height = normheight+'px';
		document.getElementById("shadow").style.height = normheight+'px';
		document.getElementById("mainbbg").style.height = normheight+'px';		
		document.getElementById("shdw_bg").style.height = (normheight-480)+'px';
		//alert(normheight);
		}
	
	}

window.onload=showback;
window.onresize=showback;