Function Problem

[Arjun_Sarankulu]

I have created Following Function which takes 2 parameter

CREATE OR REPLACE FUNCTION Inst_Param_Desc(constant_Val IN varchar2(2), display_name1 IN varchar2(40)) 
   RETURN VARCHAR2 
   IS Front_Display_Name VARCHAR2(40);
   Enum_Id number(4,0);
   
   BEGIN 
      
      
      select b.enumeration_id into Enum_Id from xyz b where b.display_name = display_name1;
      
      SELECT a.front_end_display_name 
      INTO Front_Display_Name
      from abc a
      where a.enumeration_id = Enum_Id
      and a.constant_value  = constant_Val;
      
      RETURN Front_Display_Name; 
      
    END Inst_Param_Desc;

I am not getting what is wrong with my code

[Arjun_Sarankulu]

Error(1,50): PLS-00103: Encountered the symbol "(" when expecting one of the following: := . ) , @ % default character The symbol ":=" was substituted for "(" to continue.

[Arjun_Sarankulu]

CREATE OR REPLACE FUNCTION Inst_Param_Desc(constant_Val IN VARCHAR2, display_name1 IN VARCHAR2)
RETURN VARCHAR2
IS Front_Display_Name VARCHAR2(40);

BEGIN

SELECT a.front_end_display_name
INTO Front_Display_Name
from ATS_CONSTANTS a
inner join ATS_ENUMERATIONS b on b.enumeration_id = a.enumeration_id
where b.display_name = display_name1
and a.constant_value = constant_Val;

RETURN Front_Display_Name;

END;

[Arjun_Sarankulu]

Error(1,50): PLS-00103: Encountered the symbol "(" when expecting one of the following: := . ) , @ % default character The symbol ":=" was substituted for "(" to continue.

Error(1,80): PLS-00103: Encountered the symbol "(" when expecting one of the following: := . ) , @ % default character The symbol ":=" was substituted for "(" to continue.

Error(1,26): PLS-00103: Encountered the symbol "@" when expecting one of the following: <an identifier> <a double-quoted delimited-identifier> current