John,

>Error: Cannot implicitly convert type 'object' to 'decimal'

My syntax might not be right and I might be misunderstanding "casting" (I'm not a C# expert), but can you force a conversion to decimal in the return statement... something like this?

return (decimal)b.getbalance(custNumber);

Or perhaps store the return value to a var first that is forced to decimal, then return that?

decimal retvalue = (decimal)b.getbalance(custNumber);
return retvalue;