package to check if the input chars are number

gurus,

is there a package that can check if the input is a numeric or varchar when the variable has a varchar2 type?

e.g. user input '123' === output is numeric

                             '2rY' === output  not numeric

thanks    

Grace Lim
Suy Sing Comm'l Corp. Received on Thu Jul 06 2000 - 03:59:04 CDT