下面这个是移动form自己的：
var
lastx,lasty:Integer;
procedure TFormDateTime.FormMouseDown(Sender: TObject;
Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
lastx:=x;
lasty:=y;
end;
procedure TFormDateTime.FormMouseMove(Sender: TObject; Shift: TShiftState;
X, Y: Integer);
begin
if ssLeft in shift then
Begin
left:=left+x-lastx;
top:=top+y-lasty;
End;
end;