New appointement

Hello, I want open a new tab Appointment in zimbra.
I have see that it's possible for a new message.I think replace "GetComposeController" by "GetCalController" and "NEW_MESSAGE" by "NEW_APPOINTEMENT"... but fail!

Code:

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function Compose_Mail_Example() {
}

Compose_Mail_Example.prototype = new ZmZimletBase();
Compose_Mail_Example.prototype.constructor = Compose_Mail_Example;

Compose_Mail_Example.prototype.doubleClicked = function() {
    this.singleClicked();
};

Compose_Mail_Example.prototype.singleClicked = function() {
        // Tries to open the compose view on its own.
        var composeController = AjxDispatcher.run("GetComposeController");
        if(composeController) {
                var newWindow = false;
                //to field content
                var to = "a";
                //subject field content
                var subject = "example subject";
                //body content
                var body = "example body";
                var params = {action:ZmOperation.NEW_MESSAGE, inNewWindow:newWindow,
                toOverride:to, subjOverride:subject, extraBodyText:body, callback:null}
                composeController.doAction(params); // opens asynchronously the window.
        }
};

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HELP ME!

Tanks...