javascripthtml5实现表单验证_javascript技巧

　　 fieldset{border: 0;}
  .myform .form-control{
    display: block;
    padding: 5px;
    width: 100%
  }
  .myform input:focus:invalid + .form-error{
    display: inline;
  }
  .myform .form-error{
    display: none;
    position: absolute; 
    margin-top: .7em;
    padding: 1px 2px;
    color: #fff;
    font-size: .875rem;
    background: #f40;
  }
  .myform .form-error:after{
    position: absolute;
    content: "";
    top: -.5em;
    left: .5em;
    z-index: 100;
    display: inline-block;
    width: 0;
    height: 0;
    vertical-align: middle;
    border-bottom: .5em solid #f40;
    border-right: .5em solid transparent;
    border-left: .5em solid transparent;
    border-top: 0 dotted;
    transform: rotate(360deg);
    overflow: hidden;
  }
  .btn{
    padding: 5px 20px;
   }