Question

I am using the following regular expression to validate a comma delimited list of email addresses. It works great as long as the input is such that each email address does not have leading and trailing blanks. I would like to accept leading and trailing blanks for each email address within this list. How can I do this?

   <asp:RegularExpressionValidator ID="emailAddressesListValidator"  Display="Dynamic"
     ControlToValidate="stringTextBox" runat="server"  ForeColor="Red" 
     ErrorMessage="Invalid List. Please input a comma separated list of email addresses."
     ValidationExpression="^((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,])*)*$"> 
   </asp:RegularExpressionValidator>

Answer 1

I was able to get it to work by changing the regular expression to the one below.

ValidationExpression="^(\s*(\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,])*\s*)*$"