获取select值及判断是否是数字

代码片段

<div class="container-fluid">
    <div class="row">
        <div class="col-md-6 col-md-offset-3">
            <div class="panel panel-default m-top">
                <div class="panel-heading">添加</div>
                <div class="panel-body">
                    <form method="" action="" class="form-horizontal">
                        <div class="form-group form-group-sm">
                            <label for="productNos" class="col-sm-4 control-label">名称：</label>
                            <div class="col-sm-4">
                                <select name="productNo" id = "productNos" class="form-control">
                                    <option value="">--请选择--</option>
                                    <option value="010">动联</option>
                                    <option value="009">BBPOS</option>
                                    <option value="008">天喻</option>
                                    <option value="007">江苏怡丰</option>
                                    <option value="006">赢联</option>
                                    <option value="005">华中星（鼎合）</option>
                                    <option value="004">新大陆</option>
                                    <option value="003">智嘉</option>
                                    <option value="002">升腾</option>
                                    <option value="001">艾创</option>
                                </select>
                            </div>
                            <div class="col-sm-4">
                                <span class="msg1"></span>
                            </div>
                        </div>
                        <div class="form-group form-group-sm">
                            <label for="proNum" class="col-sm-4 control-label">数量：</label>
                            <div class="col-sm-4">
                                <input type="text" id="proNum" name="proNum"  class="form-control" />
                            </div>
                            <div class="col-sm-4">
                                <span class="msg2"></span>
                            </div>
                        </div>
                        <div class="col-sm-offset-4">
                            <button type="submit" class="btn btn-primary btn-sm" onclick="return create();">
                                <i class="glyphicon glyphicon-saved"></i>
                                <span>保存</span>
                            </button>
                            <button onclick="back();" class="btn btn-sm btn-danger" type="button">
                                <i class="glyphicon glyphicon-remove-circle"></i>
                                <span> 取消</span>
                            </button>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</div>
    
<script type="text/javascript">
function create(){
    var productNo = $("#productNos").val(); // 获取select 的value值
    if(productNo == ""){
        layer.msg("请选择厂家名称!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
        return false;
    }
    var proNum = $("#proNum").val();
    if(proNum == ""){
        layer.msg("请输入数量!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
        return false;
    }else{
        if(isNaN(proNum)){ // 如果是数字则返回 false 
            layer.msg("请输入数字!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
            return false;
        }
    }
}
</script>