var myWindowHeight		= 0;
var myWindowWidth		= 0;
var isOpera				= self.opera;
var isIe				= !isOpera && document.all;
var popupOffsetLeft		= 0;
var popupOffsetTop		= 0;

//var popupWidth = 400;
//var popupHeight = 500;

function setWindowParameters() {
	if (self.screen) {
		myWindowWidth = screen.width;
		myWindowHeight = screen.height;
	} else {
		myWindowHeight = window.outerHeight;
		myWindowWidth = window.outerWidth;
	}			
	popupOffsetLeft = myWindowWidth/2 - popupWidth/2;
	popupOffsetTop = myWindowHeight /2 - popupHeight/2;			
}


if(isIe || isOpera) {
	window.attachEvent("onload", setWindowParameters);
} else {	
	window.addEventListener("load", setWindowParameters, true);
}

/*
<script language="javascript" type="text/javascript">
	var popupWidth = 400;
	var popupHeight = 500;
</script>
*/