void __fastcall MyLabelMouseMove(TObject *Sender, TShiftState Shift,
      int X, int Y)
{
   ShowMessage("Hello World !");
}

lngLabel->OnMouseMove =  MyLabelMouseMove;

 JS 

void __fastcall TForm1::MyLabelMouseMove(TObject *Sender, TShiftState Shift,
      int X, int Y)
{
   if (dynamic_cast<TLabel*>(Sender))
   {
     dynamic_cast<TLabel*>(Sender)->Color = clRed;
   }
}  

void __fastcall TForm1::LabelClick(TObject *Sender)
{
   if (dynamic_cast<TLabel*>(Sender))
    {
       Edit1->Text = dynamic_cast<TLabel*>(Sender)->Name;
    }
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
   for (int i= 1 ; i< 27 ; i++)
    {
       TLabel *lngLabel = new TLabel (Form1);
       lngLabel->Parent=Form1->Panel1;
       lngLabel->Left=i* 20 ;
       lngLabel->Top= 4 ;
       lngLabel->Caption=title;
       lngLabel->OnClick = LabelClick;
       lngLabel->OnMouseMove = MyLabelMouseMove;
    }
}

 JS