Dropdownlist Sqldatasource

I am using VB.....please help



I have two drop downs.....and five datasources. I forgot the proper syntax for this statement.
dropdownlist2.   ????????????????



I need to change the datasource of dropdown2 according to what is in dropdown 1.... like so......


If DropDownList_1.SelectedValue = "1" Then
            DropDownList2.DataSourceID = "SqlDataSource1"
        End If


If DropDownList_1.SelectedValue = "2" Then
            DropDownList2.DataSourceID = "SqlDataSource2"
        End If


If DropDownList_1.SelectedValue = "3" Then
            DropDownList2. ...