Swift Programming

Create a small program that has a text field that has the user enter in their user id and phone number. These text field only allows numbers and no other characters. IF the user enters in something other then a number, it will give the user an error. Thank you

Conditions:

1.) Two text fields : one for id, one for phone number

2.) Text fields : only allows numbers and will display an error alert if any other characters are entered

3.) Will check if both text fields are filled in, if one or the other is not, then will display an error message for the user to have to fill in both text fields before pressing enter.