[Javascript] Newbie Question - Passing Variables

[rchadwe1 at tampabay.rr.com]

function popUp(URL,wth,hgt) {
day = new Date(); 
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbars=0, 
scrollbars=0, location=0, statusbars=0, menubars=0, resizable=0, 
width= + wth + , height= + hgt + ');");

I am trying to pop up a window using variables to determine window 
size.  Trying to create a generic pop up script.  I can't get it to 
recognize the wth and hgt variables.  Can you help me? hep me hep me.

Thanks

Rob