Wei*_*Jin 1 javascript forms validation
出于某种原因,无论字段是否为空,此代码始终重定向到education.php.我想验证字段中是否有值,但由于某种原因,它们会保留重定向但不在数据库中写入任何内容.任何帮助将不胜感激.
<body>
<form action="education.php" method="post" onsubmit="return validate_fields()">
<div style="text-align: right">
<ul>
First Name: <input id="first_name" name="first_name" size=25/> <br>
Last Name: <input id="last_name" name="last_name" size=25/> <br>
Email: <input id="emailaddress" name="emailaddress" size=25/> <br>
Password: <input id="user_password" name="user_password" type="password" size=25/> <br>
<center><input type="submit" name="submit" id="submit" value="Register Now"/></center>
</ul>
</div>
</form>
<script type="text/javascript">
function validate_fields()
{
var first_name = document.getElementByID("first_name").value;
var last_name = document.getElementById("last_name").value;
alert(""+first_name+" "+last_name);
if (first_name.length < 1 || last_name.length < 1)
{
alert("Please fill in your name.");
return false;
}
var email = document.getElementById("emailaddress").value;
if (email.length < 1)
{
alert("Please fill in your email address.");
return false;
}
var password = document.getElementById("password").value;
if (email.length < 1)
{
alert("Please put in a password.");
return false;
}
alert(first_name+" "+last_name+" "+email);
return false; //was true, changed to see if still redirects.
}
</script>
</body>
你的函数的第一行有一个拼写错误,所以它没有返回false(或者是true),它根本就没有运行.这解释了为什么您没有收到任何警报以及表单提交的原因.
var first_name = document.getElementByID("first_name").value;
// you need a lowercase "d" here ------^
它应该是.getElementById(),而不是.getElementByID().
这是您可以使用适合您的浏览器的开发人员工具轻松找到的东西.Chrome内置了这个(只需按下ctrl-shift-J即可启动开发工具),或者你可以为FireFox添加Firebug,IE现在有几个版本的开发工具栏选项.