!!Determines if a string value consist of a date !Functionality: This function returns the date if the passed string is a valid date, or NULL if it is not (in the specified format) !Parameters: |STRING | The test value you want to test |FORMAT | The format of the !Returns: Date !Errors: * None Returns NULL if the value is not a date, or is not in the specified format !Notes * This is normally used in programming logic to ensure that a variable contain a date value only, so as to prevent other errors from occurring