Error while decrypting data in Asp.net 1.1

I am getting the foolowing error {"PKCS7 padding is invalid and cannot be removed." }  for the below code while decrypting .
I am able to encryt the data sucessfully but getting the above error while decrypting in the function --  public string Decrypt(string cipherText, string Password) .
Near cs.Close() giving the above exception.
 
 
 
using System;
using System.Data;
using System.Text;
using Go to the complete details ...