js jquery搜索下拉框 自动选中 搜索到结尾处从头搜索

html:

<span style="font-size:14px;"><span class="select-box" style="width:150px;"><select class="select" id="brand_id" name="brand_id" size="1" >        <option value="0" selected>- - -请选择- - -</option>        <option value="16">万利达/malata</option><option value="17">现代/HYUNDAI</option><option value="18">E人E本</option><option value="19">海信/Hisense</option><option value="20">喜之郎/STRONG</option><option value="21">阿尔卑斯/Alpenliebe</option><option value="22">春光/chun guang</option><option value="23">潘高寿</option><option value="24">皇冠/Danisa</option><option value="25">波力/PO-LI</option><option value="26">张二嘎</option><option value="27">怡达/yida</option><option value="28">母亲</option><option value="29">品客/Pringles</option><option value="30">乐事/Lay s</option><option value="31">多力多滋/Doritos</option><option value="32">康师傅/Master Kong</option><option value="33">百味林</option><option value="34">绿帝/green king</option><option value="35">上好佳/Oishi</option><option value="36">立丰/lifefun</option><option value="37">华味亨</option><option value="38">桂格/QUAKER</option><option value="39">卡夫/KRAFT</option><option value="40">维维</option></select></span><input type="text" name="search" id="searchText" onkeyup="" placeholder="品牌名称" style="width:150px" class="input-text"><button name="" id="btn_search" class="btn btn-success" type="button" onclick="searchs()" ><i class="Hui-iconfont"></i> 搜品牌名称</button></span>

JS:

    var lastSerachIndex =new Array();    lastSerachIndex.push(-1);    var lastSearchStr='';    function searchs(){        var searchText=$("#searchText").val();        if(searchText==''){return;}        var isfind = false;        if(searchText!=lastSearchStr){            lastSerachIndex.push(-1);        }        $("#brand_id option").each(function(index) {            if($(this).text().indexOf(searchText)>-1&&isfind==false&&$.inArray(index,lastSerachIndex)<0){                lastSerachIndex.push(index);                lastSearchStr=searchText;                isfind=true;                $(this).prop("selected","selected");                return false;            }            if($("#brand_id option").length==(index+1)){                lastSerachIndex.length=0;            }        })    }

效果：