From phpBB Development Wiki
confirm_box –– Present a confirmation screen which offers the user a Yes or No option. A confirmation should be used before committing any sensitive operation.
bool confirm_box ( $check [, $title [, $hidden [, $html_body [, $u_action ]]]] )
The confirm boxes are phpBB3's system to secure critical actions against CSRF attacks and unintentional triggering. The system is quite simple: the function can be called in check mode, where it will check the presence of a one-time confirmation string passed as request parameter or in display mode, where it will display the confirm box.
|check||Yes||bool||True for checking if confirmed (without any additional parameters) and false for displaying the confirm box|
|title||No||''||string - Title/Message used for confirm box. Specified as a language key used to explain to the user what action they are confirming. message text is _CONFIRM appended to title. If title cannot be found in user->lang a default one is displayed If title_CONFIRM cannot be found in user->lang the text given is used.|
|hidden||No||''||string - Hidden variables (in HTML) for passing within the script.|
|html_body||No||'confirm_body.html'||Template used for confirm box|
|u_action||No||''||string - Custom form action|
Generally, you will need to supply the first three parameters, while the remaining two are usually fine left default. The second parameter should be a language key used to explain to the user what the confirm box is about. The third parameter, $hidden, should hold html for hidden fields containing all (user-)submitted values needed to get the current script to exactly the state where it is when calling the function.
Returns true if the user confirmed the operation, false if the user cancelled or an error occurred resulting in the form being cancelled.
Example #1 Generic usage
// check mode
$s_hidden_fields = build_hidden_fields(array(
'submit' => true,
'my_message' => $my_message,
confirm_box(false, 'SAMPLE_LANG_KEY', $s_hidden_fields);