InfoPath Dev

Is there a way to force a user to select an option in a combo box in an InfoPath 2003 form? If I right click on the box and select Properties the 'Cannot be Blank' check box is greyed out.

Yes this is possible. Usually you have a default value set to your drop down list, like Select... or it is just blank.

Now select properties from your ddl and then select data validation. click add and then select from the first dropdown your ddl (e.g. field1) and in the second is blank (depending on what your default of the ddl is). You can also then use some screentips which will appear when the user trys to submit the form without a selection.

Hope this helps.