两个select来回联动

<select multiple="multiple" id="sel1">
<option value="1">ABC</option>
<option value="2">DEF</option>
<option value="3">GHI</option>
<option value="4">LMN</option>
<option value="5">OPQ</option>
</select>
<!--另一个select类似-->

$("#sel1").on("dblclick","option", function ()
{
$("#sel2").append($(this)); // apend会移动到目标父元素上
selSort(2);
});

$("#sel2").on("dblclick","option", function () {
$("#sel1").append($(this));
selSort(1);
});

$("#btnAdd").click(function ()   //单击 “加入”后
{
var isSelected = $("#sel1>option:selected");      //
//console.log(isSelected);
$("#sel2").append(isSelected);
selSort(2);
});            //“删除”类似

function selSort(i)
{

$("#sel" + i + ">option").sort(function (a, b)
{
var aText = $(a).text().toUpperCase();
var bText = $(b).text().toUpperCase();
if (aText > bText) return 1;
if (aText < bText) return -1;
//console.log(aText,bText);
//return 0;
}).appendTo("#sel" + i);
}