Some problems with string type

[Valdes <valdesl@wanadoo.fr>]

I have my program writen in Ada that raise some exceptions:

raised CONSTRAINT_ERROR : gestindex.adb:5

... And at line 5...

 function createindex (S:string) return index is
      I:Index;
   begin
      i.nameindex:=s; -- Ligne cinq
      i.firstletter:=null;
      return i;
   end createindex;

... The index record is defined as follow...

  type index is record
      nameindex:String(1..20);
      firstletter:ptrletter;
   end record;

... The mistake seems to be trivial but I don't see it.

I have seen the same for this also:

    Ptrtemp.Letter:=Charat(M,Ni);

there is the same error but Charat return a character and letter is also
one. (ptrtemp is also type ptrlettre)

All my greetings if you have some ideas. And forgive me for my bad
english.

--
Le Vif Z�phyr Jubile Sur Les Kumquats Du Clown Gracieux.