exercice convertir un entier décimal

program ex1;
uses wincrt;
var
ch:string;
n:integer;


procedure saisie(var n:integer);
begin
repeat
writeln('donner l''entier');
readln(n);
until n>0;
end;



function conv_10_2(n:integer):string;
var
r:integer;
ch:string;
begin
ch:='';
repeat
r:=n mod 2;
n:=n div 2;
conV:=(r,chi);
ch:=chi+ch;
until (n=0);
conv_2_10:=ch;
end;

begin
saisie(n);
ch:=conv_10_2(n);
write(ch);
end.