Limiting the number of submissions to a particular event can prove useful, when you are using the form as a subscription form for example. To achieve this, a script in the Scripts called on form display area is required:
$database = JFactory::getDBO();
$database->setQuery("SELECT COUNT(`SubmissionId`) FROM #__rsform_submissions WHERE `formId`='2'");
if (intval($database->loadResult()) >= 50)
echo 'Sorry, no more submissions are accepted !';
$formLayout = '';
The above example will limit the submissions for the form that has id = 2. If the limit is reached (50 submissions in this example) the actual form will be replaced with a warning message.