var dom=document.getElementById
var win= null;
var screenW=screen.width;
var screenH=screen.height; 
buttonImage1 = new Image();
buttonImage1.src="images/am_clock.gif"; // preload this  
// centers pop-up window on screen 
function NewWindow(mypage,myname,w,h,scroll){
	 var winl = (screenW-w)/2;
	 var wint = (screenH-h)/2;
	  var settings  ='height='+h+',';
	      settings +='width='+w+',';
	      settings +='top='+wint+',';
	      settings +='left='+winl+',';
	      settings +='scrollbars='+scroll+',';
	      settings +='resizable=yes';
	  win=window.open(mypage,myname,settings);
	  if(parseInt(navigator.appVersion) >= 4){win.window.focus();}
}