Modify External Browser Element via Vb.Net - vb.net

Question

Is that anyway to Modify firefox (or other browser) element with Watin/VB.Net after it open?
For example, I have a blank html page, then i open that page with Watin. Because its blank so no element loader. Then i want to add element to that page (form or link or image). Is that possible?
Or is it possible to done with memory editing? or maybe javascript?
so far the closest thing that i can find is this javascript
<button onclick="openTab()">Open</button>
<button onclick="closeTab()">Close</button>
<script>
var TAB;
function openTab() {
TAB = window.open("", "TAB");
TAB.document.write("<p>hi</p>")
}
function closeTab() {
TAB.close();
}
</script>
but its work change the elemnt of its own page, if use another URL its not work, and also its not vb. net XD

Answer 1

The following is functional code to modify a web page (any web page) using WatiN. You will be modifying the local copy you have locally, not the one on the server, of course. You can go as crazy as you want but you need to be more specific on what you want to achieve:
var browser = new IE();
browser.GoTo("about:blank");
browser.WaitForComplete();
browser.Eval(#"document.write('This is new text on the web page<br>')");
browser.Eval(#"var buttonnode= document.createElement('input');");
browser.Eval(#"buttonnode.setAttribute('type','button');");
browser.Eval(#"buttonnode.setAttribute('name','sal');");
browser.Eval(#"buttonnode.setAttribute('value','New Button');");
browser.Eval(#"document.body.appendChild(buttonnode);");