Phone number validation in varchar2 field

Ok after set this format mask,If the user enter character then,The error will throw. So how to give message to user
if he enter wrongly.

could u tell me how to translate

Hello friends,

I using two text items for CODE and NUMBER..this are number data types..Ok i met one problem now.
If the user try to insert zero in the code in starting position then it does not allowed by CODE. it automatically
truncate the zero and insert value in database. Example 02332-232434 ...What can i do

Hai every one,

Finally i done this.. I write a function to validate phone number in varchar2 field

my function is :

FUNCTION PHONE_VALIDATION(PH_IN in varchar) RETURN NUMBER IS

chr char;
asci number;
no number;
v_str varchar2(20):=PH_IN;
BEGIN
     
for i in 1..length(v_str)
loop
chr:=substr(v_str,i,1);
asci:=ascii(chr);
if asci not between 48 and 57 then
no:=0;
end if;
exit when no=0;
end loop;
RETURN NO;

END;




I called this function from when validate trigger of the phone and code fields as follows


DECLARE
RESULT NUMBER;
BEGIN
     RESULT:=PHONE_VALIDATION(:PH_NO);
          IF(RESULT=0)THEN
     MESSAGE('Please Enter valid phone number');
MESSAGE('Please Enter valid phone number');
     --:PH_NO:=NULL;
     RAISE FORM_TRIGGER_FAILURE;
     -- :CONTACT_PHONE_NO:=:ph_code||'-'||:ph_no;
          END IF;
END;



finally i put this code and phone number in database column as follows :

:CONTACT_PHONE_NO:=:PH_CODE||'-'||:PH_NO;

Hai every one i done this...