# OnClientDropDownSelectedIndexChanging

The **OnClientDropDownSelectedIndexChanging** client-side event occurs when the user is changing the selected item in the DropDown.

1. The instance of the **ribbonbar** firing the event

2. An **eventArgs** parameter containing the following methods:

   * get_dropDown()

   * get_index()

   * get_cance()

   * set_cancel()