// 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);
	
	myWidth = objBody.offsetWidth;
	myHeight = objBody.offsetHeight;

	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;
	}
	
}