Edit The Code:
See Result »
Try it Yourself - ©
w3ii.com
<!DOCTYPE html> <html> <body> <h1>My First JavaScript</h1> <p id="demo">JavaScript can change the style of an HTML element.</p> <script> function myFunction() { document.getElementById("demo").style.fontSize = "25px"; } </script> <button type="button" onclick="myFunction()">Click Me!</button> </body> </html>