The event of ActiveX Control

<Script language="javascript">
function onCallBack(){
    //Do something
}
 
window.onload = function(){
    var yourActiveXObject = document.getElementById('UserControl1');
    if(typeof(yourActiveXObject) === 'undefined' || yourActiveXObject === null){
        return;
    }
 
    // attach events
    var status = yourActiveXObject.attachEvent('EventName', onCallBack);
}