//--- open a popup window
function popup(page, h, w, t, l, windowScroll){
		defaultHeight = 300;
		defaultWidth = 400;
		defaultTop = 100;
		defaultLeft = 100;
				
		if(h==null) h=defaultHeight;
		if(w==null) w=defaultWidth;
		if(t==null) t=defaultTop;
		if(l==null) l=defaultLeft;
		if(windowScroll==null) windowScroll="no";
		
		popupWindow = window.open(page, "Popup", "status=no,tool=no,scrollbars="+windowScroll+",height="+h+",width="+w+",top="+t+",left="+l);

}