JavaScript不允许在运行前输入

Question

Im having issues with this javascript running prior to the user input, can someone help me fix this.

im just trying to make a little html page with a textbox and a button, that then clicked opens a new windows with a modified URL.

<input type="text" name="enter" class="enter" value="" id="lolz" />
<button type="button" id="the_button">Count</button>

document.getElementById('open').addEventListener('click', myFunction());
function myFunction() {
  var button = document.getElementById("the_button");
  var siteid = document.getElementById('lolz').value
  button.onclick = count();

  function count() {
    window.location = "http://www.websiteimusing.com/" + siteid;
  }
 }

You can check the code out here The Actually generate output from that website's code is this

Updated Code

document.getElementById('the_button').addEventListener('click', myFunction);
 function myFunction() {
   var button = document.getElementById("the_button");
   var siteid = document.getElementById('lolz').value
    button.onclick = count();

 function count() {
     window.location = "http://www.websiteimusing.com/" + siteid;
   }
  }

Answer 1

Change to:

document.getElementById('open').addEventListener('click', myFunction);

When you put () after a function name, it means to call the function at that time.

Answer 2

There's no element with id open in your code, so you're trying to add an event listener to null. The console will tell you the same:

Uncaught TypeError: Cannot call method 'addEventListener' of null

Also make sure to remove the parens from your event listener function, as the other posters have stated.

Answer 3

On this line

document.getElementById('open').addEventListener('click', myFunction());

you are calling the function by adding the ()

change that to:

document.getElementById('open').addEventListener('click', myFunction);