'Move to the next bookmark'

def GotoNextBookmarkEvent(self, event, fromPos=(-1)):

    if (fromPos == (-1)):
        (fromPos, end) = self.GetSel()
    startLine = (self.LineFromChar(fromPos) + 1)
    nextLine = (self.GetDocument().MarkerGetNext((startLine + 1), MARKER_BOOKMARK) - 1)
    if (nextLine < 0):
        nextLine = (self.GetDocument().MarkerGetNext(0, MARKER_BOOKMARK) - 1)
    if ((nextLine < 0) or (nextLine == (startLine - 1))):
        win32api.MessageBeep()
    else:
        self.SCIEnsureVisible(nextLine)
        self.SCIGotoLine(nextLine)
    return 0
