Methods are not getting invoked for ExternalWidget

Migrateduser

Following javascript code is written to implement external widget.

var d2OpenAjaxHub = new D2OpenAjaxHub();
function connectCompleted(hubClient, success, error) {
if (success) {
console.log("Hub client connected");
alert("Hub client connected");

    } else
        console.log("Hub client NOT connected - please check console");
}

/* Callback that is invoked upon widget activation*/
function onActiveWidget(bActiveFlag) {
    alert("onActiveWidget");
}

/* Callback that is invoked upon widget activation*/
function onDisplayedWidget(bDisplayedFlag) {
    alert("onDisplayedWidget");
}
function onInitWidget(message)
{
alert("onInitWidget");
}

function loadEvent() {
alert("load event ");

                    // Connect hubclient 
        d2OpenAjaxHub.connectHub(connectCompleted,onInitWidget,onActiveWidget);
        alert("load event end ");
      d2OpenAjaxHub.subscribeToChannels ("D2_EVENT_SELECT_OBJECT", eventHandlerCallback, true /*handle when inactive*/);

}

function eventHandlerCallback(name, msg) {

    alert("eventHandlerCallback");
}

function publishObjectSelection()
{

}

Following callback methods 'connectCompleted,onInitWidget,onActiveWidget' are not getting invoked while widget is getting initialized and activated.
Can you let us know if there is any wrong in my implementation.