OnSend JavaScript Function

OnSend.js

var sendEvent;
function onSendEvent(event) {
    /// <summary>
    /// OUTLOOK SEND EVENT
    /// Entry point for Message onSend event
    /// Per example: https://github.com/OfficeDev/Outlook-Add-in-On-Send/tree/master/outlook-add-in-on-send
    /// Setup mailbox policy first: 
    /// 1) Get sessions and commands: https://technet.microsoft.com/en-us/library/jj984289(v=exchg.160).aspx
    /// 2) Set policy and more info: https://dev.office.com/docs/add-ins/outlook/outlook-on-send-addins
    /// </summary>
    /// <param name="event" type="object">ItemSend event is automatically passed by on send code to the function 
    //                                    specified in the manifest.</param>
    sendEvent = event;

    // do your work here... since it will likely be ASYNC, you will want to
    // set the event handler to a global. When you are done, you will issue
    //  > sendEvent.completed({ allowEvent: true }); // to send
    //  > sendEvent.completed({ allowEvent: false }); // to block
    doSomething.Async(values, asyncComplete);
}