function Popup(){
}
//
Popup.prototype.open = function (url, width, height, toolbar, scroll, center) {
	var d = new Date();
	var name = (d.getTime()).toString();
	toolbar = toolbar ? "yes" : "no";
	scroll = scroll ? "yes" : "no";
	var features = "toolbar="+toolbar+",menubar="+toolbar+",location="+toolbar+",status="+toolbar+",scrollbars="+scroll+",resizable="+scroll;
	if (width) features += ",width="+width;
	if (height) features += ",height="+height;
	if (center) {
		if (width && window.screen.availWidth) {
			var x = Math.round ((window.screen.availWidth - parseInt (width)) / 2);
			features += ",screenX="+x+",left="+x;
		}
		if (height && window.screen.availHeight) {
			var y = Math.round ((window.screen.availHeight - parseInt (height)) / 2);
			features += ",screenY="+y+",top="+y;
		}
	}
	return window.open (url, name, features);
}
//
Popup.prototype.center = function (url, width, height) {
	return this.open (url, width, height, false, false, true);
}
//
Popup.prototype.centerChrome = function (url, width, height) {
	return this.open (url, width, height, true, false, true)
}
//
Popup.prototype.centerScroll = function (url, width, height) {
	return this.open (url, width, height, false, true, true)
}
//
Popup.prototype.centerChromeScroll = function (url, width, height) {
	return this.open (url, width, height, true, true, true)
}