# OnClientComboBoxSelectedIndexChanging

The **OnClientComboBoxSelectedIndexChanging** client-side event occurs when the user is changing the item in the ComboBox.

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

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

   * **get_comboBox()**

   * **get_cancel()**

   * **set_cancel()**

   * **get_index()**