Question #41420298

What is wrong with this basic Javascript code?

HTML

<h1 id="title">JavaScript Example</h1>

  <input type="text" id="myTextBox" />
  <input type="submit" value="Click Me" id="submit" />

JavaScript

function substitute() {
        var myValue = document.getElementById("myTextBox").value;
        if (myValue.length == 0){
          alert('Please enter a real value in the text box!');
          return;
        }
        var myTitle = document.getElementById('title');
        myTitle.innerHTML = myValue;
}
document.getElementById("submit").addEventListener("click", substitute);