Mask for alphaNumeric and variable mask length?

[Delicious!]

Is there a way for me to set the mask that will allow only numbers and letters (of any case)?  I looked at the documentation and can only see a way to set the mask to be either a number or a letter.  There is the mask a, but that allows users to enter symbols.

Also, is there a way for me to define a mask where I don't know the length of text the user will be entering?  For example, if I have a field for lastName I won't know the length of the name, but I'd like to restrict this field to letters only. 

[Shinu]

Hi Ohrange,

Try adding following event handler to OnKeyPress of RadTextBox in order to get the required functionality.

aspx:

<telerik:RadTextBox ID="RadTextBox2" runat="server">
    <ClientEvents OnKeyPress="OnKeyPress" />
</telerik:RadTextBox>

JavaScript:

<script type="text/javascript">
    function OnKeyPress(sender, args) {
        var keyCode = args.get_keyCode();
        if (!((keyCode > 47 && keyCode < 58) || (keyCode > 64 && keyCode < 91) || (keyCode > 96 && keyCode < 123))) {
            args.set_cancel(true);
        }
    }
</script>

Cheers,
Shinu.