function redraw(elem) {

	if (elem == "harddrives") 
	{
		//document.getElementById('harddrives').style.color='black';
		if(document.getElementById('harddrives') != null)
		{		
			document.getElementById('harddrives').style.display='block';
			document.getElementById('harddrives').style.visibility='visible';
		}
		if(document.getElementById('batteries') != null)
		{		
			document.getElementById('batteries').style.display='none';
			document.getElementById('batteries').style.visibility='hidden';
		}
		if(document.getElementById('exstorage') != null)
		{		
			document.getElementById('exstorage').style.display='none';
			document.getElementById('exstorage').style.visibility='hidden';
		}

	} 
	else
		if (elem == "exstorage")
		{
			if(document.getElementById('exstorage') != null)
			{		
				document.getElementById('exstorage').style.display='block';
				document.getElementById('exstorage').style.visibility='visible';
			}
			if(document.getElementById('harddrives') != null)
			{		
				document.getElementById('harddrives').style.display='none';
				document.getElementById('harddrives').style.visibility='hidden';
			}					
			if(document.getElementById('batteries') != null)
			{		
				document.getElementById('batteries').style.display='none';
				document.getElementById('batteries').style.visibility='hidden';
			}		
		}		
		else 
		{
			if(document.getElementById('batteries') != null)
			{
				document.getElementById('batteries').style.display='block';
				document.getElementById('batteries').style.visibility='visible';
			}
			if(document.getElementById('harddrives') != null)
			{
				document.getElementById('harddrives').style.display='none';
				document.getElementById('harddrives').style.visibility='hidden';
			}
			if(document.getElementById('exstorage') != null)
			{		
				document.getElementById('exstorage').style.display='none';
				document.getElementById('exstorage').style.visibility='hidden';
			}			
		}

	//var box = document.getElementById(elem);
	//var x_box = box.offsetHeight;
	//document.getElementById("stretcher").style.height = (x_box + 0) + "px";

}