I had created an InfoPath form using InfoPath 2010 that had a dropdown list (populated from a data connection to a custom SharePoint list). I then filtered the dropdown list based on a field called Event ID which was populated by a variable that was passed (via the URL) when the form was opened (using a jscript onLoad event). Everything worked perfectly... then the problems started. A lot of people in our company still have InfoPath 2003 and 2007 (and, no, we don't have Enterprise edition, so we can't just make it a web browser form). So, I was instructed to plan for the lowest common denominator. So, I downgraded all the data connections to 2003 compatible and made a few other changes, and all seemed good... except the filtered dropdown list. The dropdown list shows up empty. I can remove the filter, and it shows all the items from the SharePoint list, but if I put the filter back on it shows nothing. I even just tried filtering based on a certain ID, still no results return. So, my question is as follows, is it not possible to filter a dropdown list using InfoPath 2003 compatibility? It seems so simple, but I can't find an answer anywhere. Does anyone have a solution for this that doesn't involve enormous amounts of custom coding? I really appreciate any help!