audio_form object
This method returns a value indicating whether the specified control is checked.
bool is_checked(int control_id)
Parameters:
control_id
The ID of the control you wish to check.
Return value:
true if the control is checked, false if the control is unchecked or if an error occurred.
Remarks:
This method will only function on checkboxes.
Example:

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

    #include "form.bgt"

    audio_form form;

    void main()
    {
    form.create_window("Example Form", true);
    int check=form.create_checkbox("Check or uncheck me as you wish", false, false);
    int ok=form.create_button("OK");
    int cancel=form.create_button("E&xit");
    while(true)
    {
    form.monitor();
    wait(5);
    if(form.is_pressed(ok))
    {
    if(form.is_checked(check))
    {
    alert("Information", "The checkbox is checked.");
    }
    else
    {
    alert("Information", "The checkbox is unchecked.");
    }
    exit();
    }
    if(form.is_pressed(cancel))
    {
    exit();
    }
    if((key_down(KEY_LMENU))&&(key_pressed(KEY_F4)))
    {
    exit();
    }
    }
    }