function popUpCenteredWindow( url ) {
	var WinWidth = 450;
	var WinHeight = 525;
	var HorPosition;
	var VerPosition;
	//gets top and left positions based on user's resolution so hint window is centered.
	HorPosition = (window.screen.width/2) - ((WinWidth/2) + 10); //half the screen width minus half the new window width (plus 5 pixel borders).
	VerPosition = (window.screen.height/2) - ((WinHeight/2) + 50); //half the screen height minus half the new window height (plus title and status bars).
	var win2 = window.open( url ,"bannerpopup","status=0,menubar=no,toolbar=no,Directory=no,height="+ WinHeight +",width="+ WinWidth +",resizable=auto,left=" + HorPosition + ",top=" + VerPosition + ",screenX=" + HorPosition + ",screenY=" + VerPosition + ",scrollbars=yes");
win2.focus();

}