To add a drop-down form to your project, complete the following steps:

1. Right-click your project (located in the Solution Explorer) and select Add New Item from the Add sub-menu.
   
2. In the Add New Item dialog box, select Windows Form from the list of Templates in the right pane. Then enter DropDownForm1.cs in the Name textbox.
   
3. The next step is to replace the following class definition line(s) in the DropDownForm code:

   To write code in Visual Basic

   Visual Basic	Copy Code
   Public Class DropDownForm1 Inherits System.Windows.Forms.Form

   To write code in C#

   C#	Copy Code
   Public Class DropDownForm1:System.Windows.Forms.Form

   with:

   To write code in Visual Basic

   Visual Basic	Copy Code
   Public Class DropDownForm1 Inherits C1.Win.C1Input.DropDownForm

   To write code in C#

   C#	Copy Code
   Public Class DropDownForm1: C1.Win.C1Input.DropDownForm

   The form should look like the image below before editing: