Thread: how to check if input is only positive number?

i´d need a function which checks if the input isn´t positive number
and asks the user again until input is right (in C language)

i tried many things and didnt get it to work right.


first it should check if it isnt numeric and ask again

then it should check if it is zero or below and ask again

and it should work three times separately for day, month and year..

i´d appreciate help...;-)