Handler in a user control is always null

I have a drop down list in a user control. I declared a delgate and event in my control.When I am doing selectedindexChanged event. My handler is always null. Below is my code in .ascx page(user control). If I do ?radComboBox_selection_selectedItem.Text, then I can see the value.
 
public delegate void onDDLChanged(); public event onDDLChanged ddlHandler; protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { List<class1>Values = new List<class1>(); values = Class1.getallTypes(); RadComboBox_Selection.DataSource = Values; RadComboBox_Selection.DataTextField = "Activity"; RadComboBox_Selection.DataValueField = "Activity"; RadComboBox_Selection.DataBind(); } } protected void RadComboBox_Selection_SelectedIndexChanged1(object sender, EventArgs e) ...