Get name of javascript method associate with <a></a>

I write a program get Html Document from Internet and parse it. I use code like:

HtmlDocument html = webbrowser1.Document;

HtmlElementCollection tags = html.getElementsByTagName("td")

I want to retreive the name of the javascript method associating with a like: . But, tags(1).firstChild.getAttribute("onclick") return System._COMObject, not the javascript function name. So, how can I get the javascript function name?