Step Conditions - Disable When Location Field not populated

Summary:

Hi,

I am trying to disable the Submit button in the Request a New Position page via a smart tip.

The conditions I am trying to put in place are:

Disable element when there is no value selected from the Location drop down menu when the Requisition Template field has "Contingent Workers" elements selected.

I have tried doing this a number of different ways - using step conditions:

When page, has not, form field - text [^\d{2}$]

When page, has, drop down - Select a value

and for contingent workers option:

When page, has not, form field text - Contingent Workers.