var ie4 = document.all;
var ns4 = document.layers;
var ns6 = document.getElementById && !document.all; 

function centerIt(div_id, show, div_height, div_width) {
	var center_height=0;
	var center_width=0;
	
	//For non IE browsers
	if (ns6 || ns4) {
  		center_width = (window.innerWidth/2)-(div_width/2);
  		center_height = (window.innerHeight/2)-(div_height/2);
	}
	else {
		center_width=(document.documentElement.clientWidth/2)-(div_width/2);
  		center_height=(document.documentElement.clientHeight/2)-(div_height/2);
 	}

	if (center_width<0) {
		center_width=0;
	}
	if (center_height<0) {
		center_height=0;
	}
	document.getElementById(div_id).style.left=center_width+"px";
	document.getElementById(div_id).style.top=center_height+"px";
	
	if (show==0) {
		document.getElementById(div_id).style.visibility='visible';
	}
}