>While stuck on another problem I thought I'd look at this to get it working. Unfortunately there must be something I am missing.
>
>In my Master file I put this:
>
>

<script type="text/javascript" src="/jquery.js"></script>
><script type="text/javascript" src="/jquery.maskedinput.js"></script>
><script type="text/javascript">
>    $("document").ready()
>    {
>        $(".number").mask("999,999,999.99");  // Masks all element with the class='number'
>    }
>     </script>

>
>Then in my aspx page I defined a textbox like this:
>
>

<mm:mmTextBox ID="txtMinSumAssured" runat="server" BindingSource="Plan" BindingSourceMember="MinSumAssured"
>   Width="100px" class="number"></mm:mmTextBox>

>
>But I am not getting the masking to work.
>

In your mm:mmTextBox markup change class="number" to CssClass="number".