function openCenteredWindow(url, height, width, name, parms) 
	{ 	
		var left = Math.floor( (screen.width - width) / 2); 
		var top = Math.floor( (screen.height - height) / 2); 
		var winParms = "top=" + top + ",left=" + left + ",height=" + height + ",width=" + width; 
			    
		if (parms) 
		{ 
		    winParms += "," + parms; 
		} 
			    
		win = window.open(url, name, winParms); 
			    
		if (parseInt(navigator.appVersion) >= 4) 
	    { 
            win.window.focus(); 
        } 
    }