// display correct header and load url

function loadpage(which,url){
	if (!document.getElementById)
		return;
	
	document.getElementById('headersites').style.display="none";
	document.getElementById('headerindustrial').style.display="none";
	document.getElementById('headeroffice').style.display="none";
	which.style.display="block";
	
	document.getElementById('sitesFrame').src=url;
}