PARAMETER MISMATCH

[jj091849@er.uqma.ca]

Bonjour j'ai une petit programme qui a une erreur de 
parameter mismatch � la lige 49 
getelem (elem,s_elem,aut_elem,ref_elem :OUT string); 
j'aimerais savoir si vous piuver m'aider ?
Merci 
===============================================
 WITH Text_Io; USE Text_IO;   
procedure identif is  
 PACKAGE ES_Entiers IS NEW Text_io.Integer_IO(Num=> Integer);   
 

elem:string(1..32);
s_elem:string(1..32);
aut_elem:string(1..32);
ref_elem:string(1..32);
str1:string(1..12);
l1,l2,l3,l4:natural:=0;


       

PROCEDURE getelem (ka: In natural;
                str1 :In string;
                elem,s_elem,aut_elem,ref_elem :OUT string) IS
   begin 
    elem:=   "                                 ";
    s_elem:= "                                 ";
    aut_elem:="                                 ";
    ref_elem:="                                 ";
    l1:=0;l2:=0;l3:=0;l4:=0;

    put(elem);
    new_line;
    get_line(elem,last=>l1);
    skip_line;
    put("source : ");
    get_line(s_elem,last=>l2);
    skip_line;
    if ka=1 then
        put("auteur ");
        get_line(aut_elem,last=>l3 );
     end if;   
        
    put("referances : ");
    get_line(ref_elem,last=>l4);
end getelem;

   ka:natural:=0;

begin 
 
    put("ka : ");
    es_entiers.get(ka);
    str1:="prenom      ";
    getelem (elem,s_elem,aut_elem,ref_elem :OUT string); 
        
   end identif;