In MS-Access, you can select a special value for your combo boxes called:

"Find a record on my form based on the value I selected in my combo box"

In older versions of MS-Access, all you had to do is select the option and be done with it. However, the option would have no effect if the form was not properly assigned a source query.

In order to paliate to that problem, Microsoft decided to check the current form status and, if unlinked, hide the option altogether so you cannot make a mistake.

The problem is that for many people the train of thought was not automatically that way. If you are like me (and many others) you probably will put all the elements on the form and start making them look nice before you actually do anything in regard to linking the form to a table or query. This means you won't be able to do the set up the way you wanted it... at least not until you select a source.

You already have a source and this option still doesn't show up? In MS-Access 2007 they added another trust level. You have to tell MS-Access that you trust the source database before it accepts to link to it with that special quite useful feature.

Source Thread was deleted...
To trust your folder, click:
* Office Button (top left)
* Access Options (bottom of dialog)
* Trust Center (left)
* Trust Center Settings (button)
* Trusted Locations (left)
* Add new location (button)