GUICtrlCreateList() Help

[=sinister=]

I have Dual Listbox's (Created by the form from Koda) and I want the buttons to work, however I cannot seem to delete one item from the list.

GUICtrlSetData($KeepList, "") Clears the entire list.

GUICtrlSetData($KeepList, "blabla") adds to the list.

Here is my layout:

$OptionsGUI = GUICreate("Options", 353, 256, 316, 131)
$RejectList = GUICtrlCreateList("", 8, 8, 137, 201)
$Add = GUICtrlCreateButton(">", 156, 15, 30, 25, 0)
$AddAll = GUICtrlCreateButton(">>", 156, 48, 31, 25, 0)
$Remove = GUICtrlCreateButton("<", 157, 81, 31, 25, 0)
$RemoveAll = GUICtrlCreateButton("<<", 157, 114, 32, 25, 0)
$KeepList = GUICtrlCreateList("", 200, 8, 137, 201)
GUICtrlSetData(-1, "Key Of A|Key Of Ab|Key Of B|Key Of Bb|Key Of C|Key Of C#|Key of Cb|Key Of D|Key Of Db|Key Of E|Key Of E#|Key Of Eb|Key Of F|Key Of G|Key Of Gb")
$OK = GUICtrlCreateButton("&OK", 104, 225, 75, 25, 0)
$Cancel = GUICtrlCreateButton("&Cancel", 184, 225, 75, 25, 0)
GUISetState(@SW_Hide, $OptionsGUI)

[GaryFrost]

_GUICtrlListBox_DeleteString