function  centWin(url, w, h, sb){
	//Uncomment for default Width and Height...
	// w = width
	// h = height
    //var w = 320;
	//var h = 300;

	var wndHeight = h;
	var wndWidth = w;
	var X = 0;
	var Y = 0;
	if (screen.availWidth){
		X = (screen.availWidth / 2) - (wndWidth / 2);
		Y = (screen.availHeight / 2) - (wndHeight / 2);
	}
	
	window.open(url, "pop_up","left=" + X + "screenX=" + X + "screenY=" + Y + ",top=" + Y +
	",toolbar=0,scrollbars=" + sb + ",resizable=0,height=" + h + ",width=" + w);
}