js with set function and using javascript to set value...

I'm using this javascript to set values of various max objects:

function anything(){
post("nexample",messagename,arguments[0]);
var knob = this.patcher.getnamed(messagename);
knob.set(arguments[0]);
}

if I try to "set" the value of a jsui this way, I get the error:

• error: js: junk.js: Javascript TypeError: knob.set is not a function, line 4
• error: js: error calling function jsknob

But the jsui does have a "set" function in it!
This happens in Max 4x and Max 5.

Here's a patch that illustrates this, call the above javascript "junk.js":