Validating input

[devaeron]

how to validate any input...

my case is just like this....

I want a user enter a student ID number which is only include 11 digits of numbers without any character on it...
I want, whenever the user inputs more or less than 11 digits, the program will display error message. whenever the user input character on it, it also display error message..

please help me..

thanks before...

[Bazzy]

I suggest you to get the input on a string (so you could know immediately its length) and then you chould check for each character of that string if it isdigit

[devaeron]

thanks.. for the info..