Weird! It worked for a moment and now it does not work again!

>>>>Might you have the variable "NULL" set to an empty string somewhere?
>>>>
>>>>good luck
>>>>
>>>IF .lAddblank
>>> =MESSAGEBOX(.name + " null? " + TRANSFORM(ISNULL(this.aRowSource[1,2])))
>>> endif
>>>
>>>Shows .t. Why would it change to blank?
>>
>>Maybe you're looking at the wrong one.
>
>No, it was the one. But I just found that changing BoundTo property of the combobox solves the problem. With boundto = .f. it sets the value to blank instead of NULL. With this property set to true, it shows NULL, as I need.