title: how back the the first index after scroling to the last index on listbox
body: <p>I use this code to move to next index <code>listBox1.SelectedIndex = listBox1.SelectedIndex +1;</code> 
  but the problem is when I am on the last index and I click the button next that have that code is crash any suggestions to make next button back to the first index after click it ??</p>