procedure TForm1.Button2Click(Sender: TObject);
var i:integer;
begin
try
strtoint(edit1.text);
i:=1;
except
try
strtodatetime(edit1.text);
i:=2;
except
i:=3;
end;
end;
case i of
1:showmessage('integer');
2:showmessage('datetime');
3:showmessage('string');
end;
end;