DataRepeater next item with manual binding navigator not wor

I have created manually in my windows applications forms a  datarepeater and i have added a binding source navigator

Below is my code

   DT.Columns.Add("c1")
        DT.Rows.Add("1")
        DT.Rows.Add("2")
        DT.Rows.Add("3")
        DT.Rows.Add("4")
        DT.Rows.Add("5")
        DT.Rows.Add("5")
        RadTextBox1.DataBindings.Add("Text", DT, "c1")
        DataRepeater1.DataSource = DT
        bindSrc.DataSource = DT
        BindingNavigator1.BindingSource = bindSrc

my problem is that when i click next in the bind navigator it is not moving to next row in datarepeater.. the next and previous button are not refreshing the datarepeater

what code should i put on the click event of the button next in the binding navigator