Question

我正在创建一个简单的表单，如果正在填充“隐藏”字段，则会发出警报，但我看不到我错过的内容或我错误的语法：

<form method="post" action="http://www.URL/form.php?form=159" id="frmSS159" onsubmit="return CheckForm159(this);">
  <input type="text" name="email" value="Email Address" onclick="this.value='';" onBlur="if(this.value=='')this.value='Email Address';" />

  <div style="padding: 5px 0;" aria-hidden="true">
    <input type="text" name="asdf" tabindex="-1" value="" placeholder="If content, alert error">
  </div>

  <input type="submit" value="Subscribe" />
</form>




    function CheckForm159() {
    if ($_POST['asdf'] != '') {
        alert("Please type your email address instead of using a form-filler");
    }
    return true;
}

fiddle

Answer 1

您的代码中有错误... 你在JavaScript中添加了$ _POST这是PHP语法。

您的更新代码......

<script> 
   function CheckForm159() {
      var _curValue = document.getElementById('asdf').value;

      if (_curValue  != '') {
         alert("Please type your email address instead of using a form-filler");
      }
      return true;
   }
</script>




<form method="post" action="http://www.URL/form.php?form=159" id="frmSS159" onsubmit="return CheckForm159(this);">
  <input type="text" name="email" value="Email Address" onclick="this.value='';" onBlur="if(this.value=='')this.value='Email Address';" />

  <div style="padding: 5px 0;" aria-hidden="true">
    <input type="text" id="asdf" name="asdf" tabindex="-1" value="" placeholder="If content, alert error">
  </div>

  <input type="submit" value="Subscribe" />
</form>

Answer 2

只需使用JQuery中的onChange函数即可。输入更改后，它将显示警告，如此。

$("input[name=asdf").change(function(){
   alert("Input value changed!");
});

JS警报问题

2 个答案: