I am having trouble with inconsistant behavior regarding regular expressions.

I use the following regexp to test for a 'strong' password: ^(?=.*[0-9]).{6,20}$

 This requires 6-20 characters with at least one digit.  The expression works PERFECTLY when I use it with System.Text.RegularExpressions' Regex.IsMatch() function.  However, the expression is ALWAY invalid when used with the RegularExpressionValidator control.  What is going on? This is a very standard regular expression.  Also, I know that R.E.Validator doesn't require the $ and ^ anchors, but the validation still doesn't work when I remove the anchors.

 Any help will be appreciated.

 -Paul

Javascript regular expressions don't support look-ahead constructs, so you'll need to turn off client script for the validator (EnableClientScript="false"). You'll also need to add a RequiredFieldValidator, since the RegularExpressionValidator ignores empty values.

Ah, I see.  I figured it was something about .NET vs. JavaScript..  didn't know Java doesn't support Look-aheads.  I knew about the RequiredFieldValidator though, but didn't mention it in order to simplify the example.

Thanks