Rahul's space

Indian PAN is as follows: AAAAA9999A:
Where First five characters are letters, next 4 numerals, last character letter
One rule there the fourth character is choosen from a list Alphabates as bellows.

C – Company
P – Person
H – HUF(Hindu Undivided Family)
F – Firm
A – Association of Persons (AOP)
T – AOP (Trust)
B – Body of Individuals (BOI)
L – Local Authority
J – Artificial Juridical Person
G – Govt

http://en.wikipedia.org/wiki/Permanent_account_number

Hence I will create a regular expression
as bellow

^[\w]{3}(p|P|c|C|h|H|f|F|a|A|t|T|b|B|l|L|j|J|g|G)[\w][\d]{4}[\w]$

Here I have a textbox and a regular expression validator in my aspx page as bellow.

<asp:TextBox ID="txtPan" runat="server" ></asp:TextBox>

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" 

     ControlToValidate="txtPan" runat="server" ErrorMessage="Invalid PAN"      ValidationExpression="^[\w]{3}(p|P|c|C|h|H|f|F|a|A|t|T|b|B|l|L|j|J|g|G)[\w][\d]{4}[\w]$">

</asp:RegularExpressionValidator>