A computer shop assembles computers using items bought from several suppliers. A text file Stock.txt contains information about each item. Information for each item is stored as a single line in the Stock.txt file in the format: <ItemNum><SupplierCode><Description> Item information is as follows: Format Comment ItemNum 4 numeric characters unique for each item in the range "0001" to "5999" inclusive SupplierCode 5 alphabetic characters to identify the supplier of the item Description a string a minimum of 12 characters The file is organised in ascending order of ItemNum and does not contain all possible values in the range. A programmer has started to define program modules as follows: Module Description SuppExists() (already written) • called with a parameter of type string representing a supplier code • returns TRUE if the supplier code is already in use, otherwise returns FALSE IsNewSupp() • called with a parameter of type string representing a new supplier code • returns TRUE if the string only contains alphabetic characters (either upper or lower case) and the supplier code is not already in use, otherwise returns FALSE