Originally, I produced a single aspx page that incorporates a calendar pop-up window which works fine. I have since recreated that page using the script from the article &#039;Create Page Templates&#039; on the Visual Studio Magazine website ( http://www.fawcette.com/vsm/2001_12/magazine/columns/aspnet/default_pf.asp# ) that places a &#039;custom page template&#039; between the Page Class and the Code Behind Class. Now when I choose a date from the calendar pop-up an error message appears that reads " &#039;window.opener.travelForm.tbFrom&#039; is null or not an object " . Could anyone let me know why this happens and/or how I can fix this, as it&#039;s rapidly becoming the bane of my existance.<BR><BR>Thank-you very much for any info.<BR><BR>