Code:
Webrowser1.Document.InvokeScript("JSfunctionsName", _
New Object() {value(0), value(1), ...})
or if function has not parameters then just
Code:
WebBrowser1.Document.InvokeScript("JSfunctionsName")
Edit: Or do you need to add your own javascript to the page?
if so then you can invoke local javascipt:
Code:
Dim code As String = File.ReadAllText(Javascript's path here)
Webbrowser1.Document.InvokeScript("execScript", New Object() {code, "JavaScript"})