[nikita.mmf]

$("form").submit(function(){
	var $notChecked = $( "input[type='checkbox']", this ).next(".warning").remove().end().not(":checked");
	if ( $notChecked.length ) {
		$notChecked.after('<div class="warning"><div id="triangle-left"></div><div class="wainfo">Выберите!</div></div>')
		return false;
	}
});