function iznumeric (
   field_value   in   varchar2 := name_in ('system.cursor_value') )
   return boolean is
begin
   if rtrim (field_value, '0123456789') is null then
      return (true);
   else
      return (false);
   end if;
end;

begin  if to_number(:CUST_TBL.CUST_NAME) = 0 then null; 
	
end if;  
message('The entry cannot be numeric');
  raise form_trigger_failure; exception  when value_error then 
  message('The entry cannot be numeric');
  
  end;

DECLARE
	v_number_found VARCHAR2(1);
BEGIN
SELECT SUBSTR(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE
  (:CUST_TBL.CUST_NAME, 0,'F_O_U_N_D'),
			1,'F_O_U_N_D'),
			2,'F_O_U_N_D'),
			3,'F_O_U_N_D'),
			4,'F_O_U_N_D'),
			5,'F_O_U_N_D'),
			6,'F_O_U_N_D'),
			7,'F_O_U_N_D'),
			8,'F_O_U_N_D'),
			9,'F_O_U_N_D'),
			'F_O_U_N_D', 1), -1,1)
	INTO v_number_found
	FROM dual;
	IF v_number_found <> '1' THEN
		MESSAGE('Name is Valid');
	ELSE
		MESSAGE('No number can come in the Customer Name');
	RAISE FORM_TRIGGER_FAILURE;
	END IF;
END;

begin
   if rtrim (upper (:CUST_TBL.CUST_NAME), ' ABCDEFGHIJKLMNOPQRSTUVWXYZ') is not null then
      message ('The entry is not all alphabetic');
      raise form_trigger_failure;
   end if;
end;