Iframe js 自适应高度

<iframe id="mainFrame" name="mainFrame" src="/zwgk/hsearchview" width="740"  frameborder="0" scrolling="no" scrolling="no" frameborder="0" >
        </iframe>        
        
         <script type="text/javascript" language="javascript">
         function reinitIframe(){ 
        	 var iframe = document.getElementById("mainFrame"); 
        	 try{ 
        	 var bHeight = iframe.contentWindow.document.body.scrollHeight; 
        	 var dHeight = iframe.contentWindow.document.documentElement.scrollHeight; 
        	 var height = Math.max(bHeight, dHeight); 
        	 iframe.height = height; 
        	 }catch (ex){} 
        	 } 
        	 window.setInterval("reinitIframe()", 100); </script>