function centerPopUp( url, name, width, height, scrollbars ) { 
 
	if( scrollbars == null ) scrollbars = "0" 
 
	str  = ""; 
	str += "resizable=1,"; 
	str += "scrollbars=" + scrollbars + ","; 
	str += "width=" + width + ","; 
	str += "height=" + height + ","; 
 
	if ( window.screen ) { 
		var ah = screen.availHeight - 30; 
		var aw = screen.availWidth - 10; 
 
		var xc = ( aw - width ) / 2; 
		var yc = ( ah - height ) / 2; 
 
		str += ",left=" + xc + ",screenX=" + xc; 
		str += ",top=" + yc + ",screenY=" + yc; 
	} 
	window.open( url, name, str ); 
}