Sort 3 number in up order

{This program sorting 3 numbers in ascending order}

program sort;

uses crt;
var
  a, b, c, x: real;

begin
  clrscr;
  write('Enter a,b,c: ');
  readln(a, b, c);
  if a > b
    then
    if b > c then         { A max, C min }
    begin
      x := a;
      a := c;
      c := x;
    end
     else
    if c < a then         { A max, B min }
    begin
      x := a;
      a := b;
      b := c;
      c := x;
    end
    else                  { C max, B min }
    begin
      x := b;
      b := a;
      a := x;
    end
  else
  if c < a then           { B max,  C min }
  begin
    x := b;
    b := a;
    a := c;
    c := x;
  end
     else
  if c < b then           { B max,  A min }
  begin
    x := b;
    b := c;
    c := x;
  end;
  writeln(a:1:2, ',', b:1:2, ',', c:1:2);
end.