testejs3.html

<!DOCTYPE html>
<html>
    <head>
        <title>Testando JS</title>
        <meta charset = "UTF-8">
        <script>
            var quebrada = false;
            function muda(tipo){
                if (!quebrada){
                    document.getElementById("luz").src= "_imagens/"+ tipo + ".jpg";
                    if (tipo == 'lampada-quebrada')
                        quebrada = true;
                }
            }
        </script>
    </head>
    <body>
        <h1>Acenda a lampada</h1>
        <img src = "_imagens/lampada-apagada.jpg" id = "luz" onmouseover = "muda('lampada-acesa')" onmouseout = "muda('lampada-apagada')" onclick = "muda('lampada-quebrada')">
    </body>
</html>