procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
var A: Char;
Tex : String;
begin
A := Key;
Key := #0;
Tex := TEdit(Sender).Text;
if (A in [#47 .. #58,#8]) then
begin
if TEdit(Sender).tag <3 then
begin
Tex[1]:=Tex[3];
Tex[3]:=Tex[4];
Tex[4]:=A;
end else
insert(A,Tex,pos('.',Tex));
TEdit(Sender).Text := Tex;
TEdit(Sender).tag := TEdit(Sender).tag+1;
end;
end;