Question on RegularExpression

[fabrice]

Hello,

In a search form, i want to permit few characters (see below) and some signs
as - _ / , .
So thios my RegularExpression and it works.

ValidationExpression="[a-zA-Z 0-9-_/,.]{4,20}"
But i'd would like to permit the sign ? in my string, but only one or two
occurence., like this.

Search : 123?456?
I don't manage to do it. All my tests are wrong.
thanks.
fabrice

[Hans Kesting]

fabrice wrote:

Hello,

In a search form, i want to permit few characters (see below) and
some signs as - _ / , .
So thios my RegularExpression and it works.

ValidationExpression="[a-zA-Z 0-9-_/,.]{4,20}"
But i'd would like to permit the sign ? in my string, but only one or
two occurence., like this.

Search : 123?456?
I don't manage to do it. All my tests are wrong.
thanks.
fabrice

You could try this:
([a-zA-Z 0-9-_/,.]+[?]?){0,2)[a-zA-Z 0-9-_/,.]*

but then you lose the maximum-length check.

explanation:
- one or more of your characters
- optionally followed by a ?
- the above repeated 0 to 2 times
- possibly followed by characters

Hans Kesting