如何链接HTML中的JavaScript程序并使其运行？

Question

Please be patient throughout this, I am VERY bad at coding both JavaScript and HTML, and this problem is probably trivial to anyone who knows anything.

For a school project, I have to create a website with a JavaScript, interactive feature. I'm planning on making a button that subsequently, when pressed, prompts the user many questions, such as "Do you have an account?", "Username?", and "Password". I believe my JavaScript is written correctly, but when I link it in my HTML, and when I press the button that is intended to start this prompting, nothing happens. What am I doing wrong?

Here are segments of both my HTML and JavaScript code that I am using.

JavaScript

function LogIn(){
var Account = prompt("Do you have an account?")

if (Account = "yes"){
    var Username = prompt("Username");
    if (Username = "MarkColley"){
        var Password = prompt("Password");

...

else{
    confirm("That keyword is not acceptable. Try 'yes' or 'no' instead.");
}
document.getElementById("demo").innerHTML = text;
}

HTML

<li><a href="CurrentShows.html">Current Shows</a></li>
<li><img src="https://cdn4.iconfinder.com/data/icons/man-and-woman/154/man-human-person-login-512.png" style="width:20px;height:20px;"><button onclick="Login()">Sign Up/Log In</button></a></li>
<script type="text/javascript" src="LogInSignUp.js"></script>
</ul>

If it helps at all, here is an image of what the button/area that I am trying to get to work looks like.

An image of my unworking, useless button.

Answer 1

Here's a fiddle with a fixed version of your code, now it works.

http://jsfiddle.net/e3xpy5tq/

What didn't work:

1. You used assignment instead of comparison (= instead of ==).

2. You missed a semicolon and a couple curly brackets .

3. Your function LogIn was misspelled on the HTML ( Login instead of LogIn ; JavaScript is case-sensitive).

    function LogIn() { var Account = prompt("Do you have an account?"); if (Account == "yes") { var Username = prompt("Username"); if (Username == "MarkColley") { var Password = prompt("Password"); } else { confirm("That keyword is not acceptable. Try 'yes' or 'no' instead."); } document.getElementById("demo").innerHTML = text; } } 

A couple suggestions:

As mentioned in some comments, go through JavaScript and HTML tutorials. Also, use a code linter in your favourite text editor. I use Sublime Text with one of its many plugins. It will help you find your errors by yourself.

Answer 2

To make the function fire you are to go this way:

<a href="#!" onclick="LogIn()">Click</a>

And to check if a value is equal to another one, you are to use the equal signs:

if(value_one === value_two)....

Because if you use the single equal sign, you are actually assigning that value to a variable.

So if you go:

if (Account = "yes"){...

You are assigning to Account the value of yes .