How to bind TextBoxes With Keypad on a Single Form in WPF

Hello,

I want to make a form in WPF with Keypad functionality and 4 Textboxes(txt1, txt2, txt3, txt4). What i want that When i click on txt1 and write anything from Keypad txt1 should get the text from Keypad. Now i click on txt2 or txt4 and start writing something, these controls should also get the text.

How i can make this functionality ??

Kindly Guide

Thanks

Jazaib Hussain