Determine If Applet Is Loaded With Javascript

I call methods in a Java applet with javascript code like this:

document.myApplet.methodName();
This works great when the applet has loaded (the JVM has started and dowloaded all the jars) but it fails if the applet hasn't loaded yet, at which point it gives an error:
Quote:

Error: Object doesn't support this property or method

Is there a way to determine that the applet is loaded or not so that I can use it in an if statement? For instance, like so:
Code:
if (isAppletLoaded()) {
document.myApplet.methodName();
}
I tried
Code:
document.myApplet == null
but that didn't work.