function user_action(user_action)
{
	form = document.getElementById('main_form');
	if(form.action.indexOf('?') != -1)
	{
		form.action = form.action+'&user_action='+user_action;
	}
	else
	{
		form.action = form.action+'?user_action='+user_action;
	}
	form.submit();
}