jquery keypress Event is not working in mobile

Hi i Have Written  Code For My Keypress Event 

Which is working Fine in Website but the same is not working in mobile

 

 

Case: i should not allow numerics in the textbox when i Press any Numeric -> this works Fine in pc but Comming to mobile it is Not working

 

i Know  all Keycodes for Mobile are same .. 

 

 Need Helpful Suggestions