asp.net validation

[EyeTalion]

I'm using the code below to format a txtbox on my web page. The code works fine, it accepts input like this: 1C232. I need to change the code so the second character could be either a number or letter...thanks.

ValidationExpression="\d{1}[a-z]\d{3}

[Memnoch1207]

have you tried

\d{1}[0-9][a-z]\d{3}

[EyeTalion]

this worked to format.

ValidationExpression="\d{1}[a-zA-Z0-9]\d{3}