// JavaScript Document
var isIE  = (navigator.appVersion.indexOf("MSIE") != -1) ? true : false;
var isWin = (navigator.appVersion.toLowerCase().indexOf("win") != -1) ? true : false;
var isOpera = (navigator.userAgent.indexOf("Opera") != -1) ? true : false;

function fnOverlay(com){
	
	var objBody = document.getElementsByTagName('body').item(0);
	var objHtml = document.getElementsByTagName('html').item(0);
	
	if( typeof( window.innerWidth ) == 'number' ) 
	{
		//Non-IE
		myWidth = window.innerWidth;
		myHeight = window.innerHeight;
  	} 
	else( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) )
	{
		//IE 6+ in 'standards compliant mode'
		myWidth = document.documentElement.clientWidth;
		myHeight = document.documentElement.clientHeight;
  	}
	
	objDiv = document.createElement("div");
	objDiv.setAttribute("id", "divOverlay");
	
	objDiv.style.height = myHeight + "px";
	objDiv.style.width = myWidth + "px";
	objDiv.style.position = "absolute";
	objDiv.style.top = "0px";
	objDiv.style.left = "0px";
	objDiv.style.zIndex = "3";
	objDiv.style.backgroundColor = "#000";
	
	if(isIE) objDiv.style.filter = "alpha(opacity=70)";
	else objDiv.style.opacity = "0.7";
	
	switch(com){
		case 'open': if(!document.getElementById('divOverlay')){
						objBody.insertBefore(objDiv, objBody.firstChild);	
					 }
		break;
		case 'close': objBody.removeChild(document.getElementById('divOverlay'));
		break;
	}
	
}