Help needed. How to validate date in PL/SQL(Oracle Web Server)

Hi,
I am working on Oracle web server3.0.
I hava a problem in validating date fields in PL/SQL. Basically I have 2 fields startdate and Enddate both are Varchar2(20)in the form which will be enterd by the users. Start date ----------(mm/dd/yyyy)
end date ------------(mm/dd/yyyy)
Because of company policy, I can use Java to validate  at the client end. Now how do I verify enterd dates are valid. Is there built in date function to validate this? Like we have in ISS(Microsoft) Isdate().

I have an other problem
Is there any fuction in Pl/Sql to validate enterd field is numeric.? Because I have amount field is varchar2(10).

Please advice me.(This is bit urgent)
Thanks,in advance. Received on Tue Apr 28 1998 - 19:58:36 CDT