$(function(){
    var availableTags = [
        '<div id="" class=""></div>',
        'document.getElementById("");',
        'alert();',
        'width: 100px;'+"n"+'height: 100px; border: 1px solid black;'
    ];

    $("#tags").autocomplete({ source: availableTags });

    $("ul.ui-autocomplete").on('click', function(){
        $('#myTextarea').val($('#myTextarea').val() + $('#tags').val());
        $('#tags').val('');
        //$("#myTextarea").val().replace(/n/g, "&#10; oooo");
    });
});