First: I'm not certain that onAction() is called for a GuiMLTextCtrl ... I recommend simply a GuiTextCtrl, there's no reason you need a multi-line one anyway.
Second: Text list columns work like this:
PHP Code:
new GuiScrollCtrl( "blah" )
{
// stuff here
new GuiTextListCtrl( "blahblah" )
{
columns = { 0, 50, 100, 120 }; // Where (the x value) at where the new column starts
addRow( 0, "Hi \t Yo \t ;o \t sup ); // You don't need the spaces, that's just to show.
}
}
Third: How are you using saveLines?
PHP Code:
array.saveLines( "path/to/file", false ); // The second paramater is to append; false to overwrite, true to append