mousedown.html

<!DOCTYPE html>
<html>
    <head>
        <script>
            function ON() {
                document.getElementById("pic").src ="../Images/bulbon.png";
            }
            function OFF() {
                document.getElementById("pic").src ="../Images/bulboff.png";
            }
        </script>
    </head>
    <body>
        <img onmousedown="ON()" onmouseup="OFF()" id="pic" src="../Images/bulboff.png">
        <p>Hold Down Mouse Button to ON Bulb</p>
    </body>
</html>