While looping pada pascal

uses wincrt;
var
a,b,c : longint;
begin
clrscr;
       a:=0;
       while (a<=10) do
       begin
b:=0;
      while (b<=10) do
begin
   write(b,' ');
b:= b+1;
end;
 writeln ('  :  ',a);
a:=a+1;
end;
readln;
end.