In data validation or with rules add a condition and there is a comparison
option for "matches pattern" in the dropdown.
Then you can pick from one of the included patterns or create your own.
Phone number is there but you can create your own custom pattern.

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Clay Fox / Microsoft InfoPath MVP
www.InfoPathDev.com / The InfoPath Authority / Downloads, Samples, How-To,
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> I'd like to know how to make a rule that says that the user needs to put in
> at least 10 numbers (like the number of digits in a US phone number). Does
> this require an expression and if so, what are the steps and details needs to
> get the expression setup up?
>
> Thank you.
follower - 26 Mar 2008 21:46 GMT
If you use a Data Validation approach with the 'matches pattern' option, that
is restricting the person to enter the numbers in a particular way (which
I've tried already).
Without asking the user to enter the numbers in a particular way, could it
be done another way?
> In data validation or with rules add a condition and there is a comparison
> option for "matches pattern" in the dropdown.
[quoted text clipped - 7 lines]
> >
> > Thank you.
Clay Fox - 26 Mar 2008 21:50 GMT
You would just add a rule to the field that after input or change to the
field it would check the condition and if it did not match the pattern could
either format it for the user using a sub string or pop a message or whatever
you wanted.

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Clay Fox / Microsoft InfoPath MVP
www.InfoPathDev.com / The InfoPath Authority / Downloads, Samples, How-To,
Experts, Forum
> If you use a Data Validation approach with the 'matches pattern' option, that
> is restricting the person to enter the numbers in a particular way (which
[quoted text clipped - 14 lines]
> > >
> > > Thank you.