I have to make a wages program for my first assignment.

Firstly
The date has to be entered. format  im using is dd, mm, yyyy
I check that month is in the range 1 - 12 - that is ok..... If user types a
alphanumeric char in ... program naturally returns with a INVALID FORMAT
error....

** Ony any procedure how can an integer response be error trapped so that no
alphanumeric characters can be entered??? -- Do use declare as integer or
which type????? **