function tx_syscbooking_submit()  {
		// add input field to invoke the reduced request
		$('filter-form-numofcourses').insert( {before:'<input id="eID" name="eID" type="hidden" value="tx_syscbooking_filter_ajax" />'} );
		var id = 'filter-form-numofcourses';	// id of the div with the content to change
		new Ajax.Updater(id, 'index.php', { 
			asynchronous: true,
			method: 'post', 
			parameters: $('filter-form').serialize()
		});
		// remove added input field
		$('eID').remove();
}

function setFormListeners() {
	new Form.EventObserver('filter-form', tx_syscbooking_submit);
}

document.observe('dom:loaded', setFormListeners);