audio_form object
This method will set the enabled and visible states of a control.
bool set_state(int control_id, bool enabled, bool visible)
Parameters:
control_id
The ID of the control you wish to change.
enabled
A boolean value indicating whether the control should be enabled.
visible
A boolean value indicating whether the control should be visible.
Return value:
true on success, false on failure.
Remarks:
The enabled/disabled flag refers to whether the control may be manipulated in any way. If set to disabled, the audio feedback will announce this and the control is unusable.
The visibility flag refers to whether the control is accessible whilst tabbing through the dialog. If it is set to invisible, the form's cursor will skip the control but the control may still be used and/or modified by the script.
Example:

    // Make a simple form with a few buttons and a listbox.

    #include "form.bgt"

    audio_form form;

    void main()
    {
    form.create_window("Example Form", true);
    int list=form.create_list("&People", 0);
    form.add_list_item(list, "Joseph", -1);
    form.add_list_item(list, "Samuel", -1);
    form.add_list_item(list, "Percival", 1);
    form.add_list_item(list, "William", -1);
    form.add_list_item(list, "Edward", 0);
    int ok=form.create_button("OK");
    form.set_state(ok, false, false);
    int cancel=form.create_button("E&xit");
    while(true)
    {
    form.monitor();
    wait(5);
    if(form.is_pressed(ok))
    {
    exit();
    }
    if(form.is_pressed(cancel))
    {
    exit();
    }
    if((key_down(KEY_LMENU))&&(key_pressed(KEY_F4)))
    {
    exit();
    }
    }
    }