html form禁止表单回车自动提交（通常原因是为在ajax提交前、后进行js判断控制）

             　@*onkeydown事件用于禁止回车自动提交form，这样就不经过js控制跳转*@
　　　　　　　　　　<form action="/Account/CheckPsw" method="post" id="login-form" onkeydown="if(event.keyCode==13){return false;}">
                 <div class="form-group has-feedback">
                     <input type="text" class="form-control" id="userName" name="userName" placeholder="请输入登录">
                     <span class="glyphicon glyphicon-envelope form-control-feedback"></span>
                 </div>
                 <div class="form-group has-feedback">
                     <input type="password" class="form-control" id="password" name="password" placeholder="请输入密码">
                     <span class="glyphicon glyphicon-lock form-control-feedback"></span>
                 </div>
                 <div class="row">
                     <div class="col-xs-12">
                         <input id="btlogin" type="button" class="btn btn-danger btn-block btn-flat" value="登 录" />
                     </div>
                 </div>
             </form>