>I'd always thought that checkboxes can have 3 values: 1 for checked, 0 for unchecked and (something else) for "Naaaaah, not sure - some of the list are and some aren't"). But I also knew, of course, that they can be T/F (never sure of the circumstances though when they're one or the other)
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>So in testing the value in code I first tested for 1 or 0. VFP gave me an operator/operand type m-m error, so I went along with it, quite happily, and tested for T/F - all well and good.
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>Since, I've made some changes to the form, but none to the checkbox logic. Now I go to test the form, click a checkbox and get an operator/operand type. In debug, the value of the checkbox is 0! So it's changed its mind!
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>Give me a break!
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>Has anyone found this problem and/or is there a definitive solution? I didn't set the initial value to the checkbox. Of course, in edit I find that it's 1. I've set it to .T. and don't get this error now. I presume it was .T. first of all - hence the first operator/operand type m-m error.
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>I've had a similar problem with listboxes not being able to decide whether their value is char or num in the past, but I can't cite a definite example now. I've had to change code that was working, testing, say for num, to that testing for char. Very frustrating.

Terry,
If they're not bound to data then by default use numeric 0/1 (unless you set the value property to T/F). When bound to data then datatype decides if it's numeric or logical.
Numeric 2 is for undetermined state (ie: null).
Cetin