ASP.Net AJAX MaskEditExtender not working Android Browser

Hi

I used below code for separate number 

cc1:MaskedEditExtender ID="MEE2" runat ="server"
            TargetControlID="Txtprice1"
            Mask="999,999,999"
            MessageValidatorTip="true"
            MaskType="Number"
            InputDirection="RightToLeft"
            AcceptNegative="Left"
            DisplayMoney="None"
            ErrorTooltipEnabled="True" />

but it didn't work in tablet (andriod Os)  I mean when I want enter number it just enter 1 number after that it change keyboad to alphabet?

is there any way that I can solve this problem?

or is there other code that I can replace it with above code?

Best Regards

Neda