using mshtml how to use oncontextmenu inC#

[nilwarude85]

private HTMLDocumentEvents2_Event _docEvent;
private mshtml.HTMLDocument doc = null;
// private string _content = string.empty;

void gmailurl_DocumentComplete(object pDisp, ref object URL)
{
//doc = null;
//mshtml.IHTMLDocument2 doc = (IHTMLDocument2)gmailurl.Document;

//mshtml.HTMLDocumentEvents2_Event iEvent = (mshtml.HTMLDocumentEvents2_Event)doc;
//iEvent.oncontextmenu += new HTMLDocumentEvents2_oncontextmenuEventHandler(Clic kEventHandler);
//foreach (IHTMLElement link1 in doc.all)
//{
// HTMLButtonElement el = link1 as HTMLButtonElement;


//}
//foreach (IHTMLElement l in doc.all)
//{


//}

//foreach (HtmlElement element in doc.all)
//{
// HTMLButtonElement btn = lk as HTMLButtonElement;


//}
//foreach (IHTMLElement link in doc.links)
//{
// // HtmlElement ele=link.

// HTMLAnchorElement anchor = link as HTMLAnchorElement;
// if (anchor != null)
// {
// HTMLAnchorEvents_Event handler = anchor as HTMLAnchorEvents_Event;
// if (handler != null)
// {
// handler.oncontextmenu += new HTMLAnchorEvents_oncontextmenuEventHandler(delegat e()
// {
// MessageBox.Show("You clicks the link: " + anchor.href);
// return true;
// });

// }
// }
//}

//_docEvent = (HTMLDocumentEvents2_Event)gmailurl.Document;
//_docEvent.oncontextmenu += new HTMLDocumentEvents2_oncontextmenuEventHandler(_doc Event_oncontextmenu);

//if (gmailurl.Document != null)
//{
// _docEvent = (HTMLDocumentEvents2_Event)gmailurl.Document;
// _docEvent.oncontextmenu += new HTMLDocumentEvents2_oncontextmenuEventHandler(_doc Event_oncontextmenu);
//}
if (doc == null)
{
doc = (mshtml.HTMLDocument)gmailurl.Document;

mshtml.HTMLDocumentEvents2_Event iEvent = (mshtml.HTMLDocumentEvents2_Event)doc;
// iEvent.onkeydown += new mshtml.HTMLDocumentEvents2_onkeydownEventHandler(k eyDown);
iEvent.oncontextmenu += new HTMLDocumentEvents2_oncontextmenuEventHandler(Clic kEventHandler);
doc.focus();
}

above code is working but textbox is disabled so give me appropriate answer