I want to be able to insert a Java applet into a web page dynamically using a Javascript function that is called when a button is pressed. (Loading the applet on page load
Create a new applet element and append it to an existing element using appendChild.
var applet = document.createElement('applet');
applet.id = 'player';
...
var param = document.createElement('param');
...
applet.appendChild(param);
document.getElementById('existingElement').appendChild(applet);
Also, make sure the existing element is visible, meaning you haven't set css to hide it, otherwise the browser will not load the applet after using appendChild. I spent too many hours trying to figure that out.