var myWidth;
var myHeight;

function CheckWidth(){
	if( typeof( window.innerWidth ) == 'number' ) { 

	//Non-IE 

	myWidth = window.innerWidth;
	myHeight = window.innerHeight; 

	} else if( document.documentElement && 

	( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) { 

	//IE 6+ in 'standards compliant mode' 

	myWidth = document.documentElement.clientWidth; 
	myHeight = document.documentElement.clientHeight; 

	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) { 

	//IE 4 compatible 

	myWidth = document.body.clientWidth; 
	myHeight = document.body.clientHeight; 

	} 
}
function adjustWidth(){
	CheckWidth();
	if (myWidth >= 800){
		if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
		  xmlhttp=new XMLHttpRequest();
		}else{// code for IE6, IE5
		  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
		xmlhttp.onreadystatechange=function(){
			if (xmlhttp.readyState==4 && xmlhttp.status==200){
				document.getElementById("main_content").innerHTML=xmlhttp.responseText;
			}
		}
		xmlhttp.open("GET","main_content.php?w="+myWidth,true);
		xmlhttp.send();
	}
}