jquery Select Change事件

eg：

<select class="form-control m-b" name="Type" id="Type">
<option selected="" value="">-所有-</option>
<option value="10">固定资产铺货单</option>
<option value="20">首次开店铺货单</option>
<option value="30">总部统配补货单</option>
<option value="40">耗材铺货单</option>
<option value="70">原材料铺货单</option>
<option value="80">农资铺货单</option>
</select>

<select class="form-control m-b" name="WorkStationType" id="WorkStationType" disabled="disabled">
<option value="50" selected="selected">下行门店</option>
<option value="51">上行门店</option>
</select>

$("#Type").on("change",
function() {
if($("#Type").val()==80)
{
//$("#WorkStationType").find("option[value = '"+50+"']").attr("selected","selected");
$("#WorkStationType option[value='50']").attr("selected","selected");
$("#WorkStationType").attr('disabled', true);

}else
{
$("#WorkStationType").attr('disabled', false);
$("#WorkStationType option[value='50']").removeAttr("selected");
}
});