Preventing other values in combo box

[cheese9799]

I have a lookup field which can take the value of one of a list of three different things. In my form, it's a combo box where I can select one of those three values. However, I can also just click into the box and type whatever I like. How do I change it so it HAS to be one of the three value list options?

I could just program it and say that it has to = (name of first) OR (name of 2nd) etc... But there must be a more elegant way since the programming method would mess up if I ever added a 4th option.

[pbaldy]

Change the Limit to List property of the combo to Yes.

[cheese9799]

Change the Limit to List property of the combo to Yes.

Didn't work.

[pbaldy]

Can you post the db? I can't imagine that not working, unless I've misunderstood the goal.