How to check number in MIPS

Hi,
I have problem with checking number typed by user in my program.
I want the user type int:

li $v0, 5
syscall

but if user type for example 123abc, then in $v0 will be only 123, and I want my program to print: "error data". Could somebody help?

P.S. Sorry for my English ;)
[315 byte] By [lucasek_20] at [2007-11-19 19:47:54]