string[] port_names; 
   
             port_names = SerialPort.GetPortNames(); 
   
             int number_of_ports = port_names.Length; 
   
   
   
             if (number_of_ports == 0) 
   
             { 
   
                 portsToolStripMenuItem.DropDownItems.Add(new  ToolStripMenuItem("No port avaliable")); 
   
             } 
   
             else 
   
             { 
   
                 for (int i = 0; i < number_of_ports; i++) 
   
                 { 
   
                   ToolStripMenuItem port_menu_item = new ToolStripMenuItem(port_names); 
   
   
   
                   portsToolStripMenuItem.DropDownItems.Add(port_menu_item); 
   
                 } 
   
             }