[HELP] DotNetBar

Umm I'm just making a injector and trying to spice things up a bit with DotNetBar but 1 problem with simple stuff like this in my code like If IO.File.Exists(ListBox1.SelectedItem) the listbox I'm using is 1 of the dotnetbar components but it tells me 'SelectedItem' is not a member of 'DevComponents.DotNetBar.ItemPanel'.
Help would be much appreciated

[php]If io.file.exists(listbox1.selecteditems(0).text) then
'bla
end if[/php]