使用外部 javascript 的 html 表单验证
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html form validation using external javascript
提问by niceApp
Friends,
朋友们，
I am trying to validate my html form using an external javascript but I am getting an error. Here are the code details:
我正在尝试使用外部 javascript 验证我的 html 表单，但出现错误。以下是代码详情：
<html>
<head>
<title>Contact US</title>
<link href="StyleSheet.css" rel="Stylesheet" type="text/css" />
<script type = "text/javascript" src = "JavaScript.js"> </script>
</head>
<body>
<h1>Contact Us</h1>
<form id = "contactUs" action="Index.htm" onsubmit = "return validateFirstName()">
<div class="row">
<span class = "label" >First Name:</span>
<span class = "formw"><input type="text" name = "fname"/> </span>
<span class = "formw"><input type="submit" name = "btnSubmit" value = "Submit" /> </span>
</div>
</form>
</body>
</html>
My external javascript file "JavaScript.js" contains the following code:
我的外部 javascript 文件“JavaScript.js”包含以下代码：
function validateFirstName() {
var x = document.forms["contactUs"]["fname"].value;
if (x == null || x == "") {
alert("First name cannot be left blank.");
return false;
}
else {
return true;
}
but when I clicked the Submit button then I get the following error:
但是当我单击“提交”按钮时，出现以下错误：
Line: 19 Error: 'validateFirstName' is undefined
第 19 行错误：'validateFirstName' 未定义
Thank You for your help in advance.
提前谢谢你的帮助。
回答by Will
You need a closing curly brace on your function.
你的函数需要一个右花括号。
function validateFirstName() {
var x = document.forms["contactUs"]["fname"].value;
if (x == null || x == "") {
alert("First name cannot be left blank.");
return false;
}
else {
return true;
}
} // <- here
回答by Eimantas Kasperiūnas
Heres my code I had wrote for checking if email inserted is valid. You can customize it to your needs, might be usefull :)
这是我编写的用于检查插入的电子邮件是否有效的代码。您可以根据自己的需要对其进行自定义，可能会很有用 :)
function readdata()
{
a=document.getElementById('email')
k=a.value
//document.write(k)
alert(k);
}
function emailValidation(elem, helperMsg) {
var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
if(elem.value.match(emailExp)){
return true;
}
else{
alert(helperMsg);
elem.focus();
return false;
}
}
Also looking at your code, you lack for curly brace at the end of your JavaScript
同时查看您的代码，您的 JavaScript 末尾缺少花括号
