I have a text box on my form that is behaving strangely. It is set up as a text box and is driven by an IIf statement. When the answer is autmatically input into the field it says either yes or no just as I want it to but........... when the cursor clicks on it it turns into a number and any reports run from this form including this field show numbers and not a yes/no answer. Can you help?

You are running it off a text box and not a combo? If you are 'looking up' the yes/no, does the lookup table have an autonumber field?
Also is there a reason why you are not using a checkbox which can only have a maximum of 3 values (Yes/No/Null) where as a textbox can have many.

The 'Yes' 'No' in the field is automatically generated by a IIf function and isn't selected by a user.

Check the format of your text box - have you got it set to yes/no and the controlsource. Check the corresponding field in the supplying table is set to yes/no also. What function are you populating the textbox from?