获取select值及判断是否是数字

代码片段
 1 <div class="container-fluid">
 2     <div class="row">
 3         <div class="col-md-6 col-md-offset-3">
 4             <div class="panel panel-default m-top">
 5                 <div class="panel-heading">添加</div>
 6                 <div class="panel-body">
 7                     <form method="" action="" class="form-horizontal">
 8                         <div class="form-group form-group-sm">
 9                             <label for="productNos" class="col-sm-4 control-label">名称：</label>
10                             <div class="col-sm-4">
11                                 <select name="productNo" id = "productNos" class="form-control">
12                                     <option value="">--请选择--</option>
13                                     <option value="010">动联</option>
14                                     <option value="009">BBPOS</option>
15                                     <option value="008">天喻</option>
16                                     <option value="007">江苏怡丰</option>
17                                     <option value="006">赢联</option>
18                                     <option value="005">华中星（鼎合）</option>
19                                     <option value="004">新大陆</option>
20                                     <option value="003">智嘉</option>
21                                     <option value="002">升腾</option>
22                                     <option value="001">艾创</option>
23                                 </select>
24                             </div>
25                             <div class="col-sm-4">
26                                 <span class="msg1"></span>
27                             </div>
28                         </div>
29                         <div class="form-group form-group-sm">
30                             <label for="proNum" class="col-sm-4 control-label">数量：</label>
31                             <div class="col-sm-4">
32                                 <input type="text" id="proNum" name="proNum"  class="form-control" />
33                             </div>
34                             <div class="col-sm-4">
35                                 <span class="msg2"></span>
36                             </div>
37                         </div>
38                         <div class="col-sm-offset-4">
39                             <button type="submit" class="btn btn-primary btn-sm" onclick="return create();">
40                                 <i class="glyphicon glyphicon-saved"></i>
41                                 <span>保存</span>
42                             </button>
43                             <button onclick="back();" class="btn btn-sm btn-danger" type="button">
44                                 <i class="glyphicon glyphicon-remove-circle"></i>
45                                 <span> 取消</span>
46                             </button>
47                         </div>
48                     </form>
49                 </div>
50             </div>
51         </div>
52     </div>
53 </div>
54     
55 <script type="text/javascript">
56 function create(){
57     var productNo = $("#productNos").val(); // 获取select 的value值
58     if(productNo == ""){
59         layer.msg("请选择厂家名称!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
60         return false;
61     }
62     var proNum = $("#proNum").val();
63     if(proNum == ""){
64         layer.msg("请输入数量!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
65         return false;
66     }else{
67         if(isNaN(proNum)){ // 如果是数字则返回 false 
68             layer.msg("请输入数字!
", {title: '提示框',icon:0,shade: [0.5],scrollbar: false});
69             return false;
70         }
71     }
72 }
73 </script>