Workaround to closing dialogs so you can quickly open another

dialogCloseAsync.js

/**
 * Closes the currently open dialog asynchronously.
 * This has an ugly workaround which is to try to set a new
 * event handler on the dialog until it fails. When it failed
 * we know the original dialog object was destroyed and we
 * can then proceed. The issue we are working around is that
 * if you call two dialogs back to back, the second one will
 * likely not open at all.
 * @param {Office.context.ui.dialog} dialog The dialog to be closed
 * @param {function()} asyncResult The callback when close is complete
 */
 function dialogCloseAsync(dialog, asyncResult){
    // issue the close
    dialog.close();
    // and then try to add a handler
    // when that fails it is closed
    setTimeout(function() {
        try{
            dialog.addEventHandler(Office.EventType.DialogMessageReceived, function() {});
            dialogCloseAsync(dialog, asyncResult);
        } catch(e) {
            asyncResult(); // done - closed
        }
    }, 0);
}