How to Execute a JavaScript when an input field gets focus

Input Example. A function is triggered when one of the input fields get focus. The function changes the background-color of the input field.

index.html

Example: HTML

First name: <input type="text" id="fname" onfocus="myFunction(this.id)"><br>
Last name: <input type="text" id="lname" onfocus="myFunction(this.id)">

<script>
function myFunction(x) {
  document.getElementById(x).style.background = "yellow";
}
</script>

Output should be:

Type:	html
Category:	Web Tutorial
Sub Category:	HTML Attribute
Uploaded by:	Admin