javascript - 当表单验证为假时，停留在当前页面

Question

如果“名称”输入字段为空，我想留在当前页面上。现在，它显示错误消息，当您单击确定时，它仍会转到下一页（contactcaptcha.php）。

function notEmpty(elem, helperMsg){
 if(elem.value.length == 0){
    alert(helperMsg);
    elem.focus();
    return false;

 }
 return true;
}




<form id="action" action="contactcaptcha.php" method="post">
    <fieldset>

      <textarea id="message" name="Message" placeholder="What's on your mind?"></textarea>

      <input id="Name" name="Name"  placeholder="Enter your full name" type="text">

      <input id="Email" name="Email" placeholder="Enter your email address" type="email">

      <input type="submit" onclick="notEmpty(document.getElementById('Name'), 'Please enter your name')" name="submit" value="Send your message">

    </fieldset>

Answer 1

像这样尝试，在元素的submit事件中返回你的函数form

<form id="action" action="contactcaptcha.php" method="post" 
 onsubmit="return notEmpty(document.getElementById('Name'), 'Please enter your name')">
    <fieldset>
     ...
     <input type="submit"  name="submit" value="Send your message">    
    </fieldset>
</form>

Answer 2

缺少return关键字：

<input type="submit" 
onclick="return notEmpty(document.getElementById('Name'), 'Please enter your name')"   
name="submit" value="Send your message">

Answer 3

当您使用 HTML5 时，您可能希望使用required 属性：http ://www.w3schools.com/html5/att_input_required.asp

<form>
  <input id="message" required>
  <input type="submit" value="Submit">
</form>