Javascript-форум - Не отрабатывает позиционирование в случае screen.width >=

Помогите пожалуйста пытаюсь научить ресурс подстраиваться под разрешение юзера а работать оно у меня не хочет....:help:

Воть код:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Yamaha motors</title>
<link href="yamaha.css" rel="stylesheet" type="text/css" />
<link href="yamaha.js" rel="edit" type="text/javascript" />

<script type="text/javascript"> 
if (screen.width >= 1600) document.getElementById('yamaha').style.left="15%"
document.getElementById('menuholder').style.left="15%"
document.getElementById('mainblocholder').style.left="15%"
document.getElementById('mainblocholder').style.top="56%"
document.getElementById('yamaha').style.top="50px"
document.getElementById(menuholder).style.top="140px";
else if (screen.width >= 1280 && screen.width < 1600) document.getElementById('yamaha').style.left="5%"
 document.getElementById('menuholder').style.left="5%"
document.getElementById('mainblocholder').style.left="5%"
document.getElementById('mainblocholder').style.top="46%"
 document.getElementById('yamaha').style.top="5px"
document.getElementById(menuholder).style.top="90px";
else if (screen.width >=1024 && screen.width < 1280) document.getElementById('yamaha').style.left="0%" document.getElementById('menuholder').style.left="0%"
 document.getElementById('mainblocholder').style.left="0%"
 document.getElementById('mainblocholder').style.top="46%"
 document.getElementById('yamaha').style.top="5px"
document.getElementById(menuholder).style.top="90px";
</script>

<style>
#mbcg { width: 100%; 
        height: 100%; 
		background-image:url(Yamaha-site-mainBCG.PNG);
		background-repeat:no-repeat;
		background-size: 100%;
		position:absolute;
		top:0;
		left:0;
		z-index: 1;
		}
		
#yamaha { position:absolute; 
          top: 5px;
		  left:0%;
		  z-index: 2;}

#menuholder { width:685px;
              height:74px;
              background-image:url(Yamaha-site-mainv2_03.png);
              background-repeat:no-repeat;
			  position:absolute;
			  top:90px;
			  left:0%;
			  z-index:2;}

#mainblocholder { width:100%px;
            	  height:100%px;
				  position:absolute;
				  top:46%;
				  left:0%;
				  z-index:2;}
				  
#mainblock { width: 825px;
             height:409px;
			 background-image:url(Yamaha-site-main_11.png);
			 background-repeat:repeat;
			 float:left;}
				  
#submenu       { width:175px;
                 height:409px;
				 background-image:url(Yamaha-site-main013.png);
				 background-repeat:no-repeat; 
				 float:left}
</style>
</head>

<body>
<div id="mbcg">
<img src="Yamaha-site-main3.png" id="yamaha" />
<div id="menuholder">
</div>
<div id="mainblocholder">
<div id="mainblock">
</div>
<div id="submenu">
</div>
</div>
</div>
[B]</body>[/B]
</html>

:-E