Oracle Error Message
PLS-00328: A subprogram body must be defined for the forward declaration of string.
Reason for the Error
A subprogram specification was declared, but the corresponding subprogram body was not defined. Write the subprogram specification and body as a unit. An alternative solution is to separate the specification from its body, which is necessary when you want to define mutually recursive subprograms or you want to group subprograms in a package.
Solution
Check the spelling of the subprogram name. If necessary, supply the missing subprogram body.