function popup(URL, width, height, scroll)
{
    if(width==null){
	    width="400px";
    }
    if(height==null){
	    height="500px";
    }	

    if(scroll==null){
	    window.open(URL,'popup',"menubar=no,resizable=yes,location=no,statusbar=no,toolbar=no,scrollbars=auto,width="+width+",height="+height+",top=170px,left=380px");	
    }	
    else{
		    window.open(URL,'popup',"menubar=no,resizable=yes,location=no,statusbar=no,toolbar=no,scrollbars=yes,width="+width+",height="+height+",top=170px,left=380px");	
    }
}