Question How can i add more than one header modifications?

[TastyTeo]

Hello i've been experimenting on some WebBrowser stuff on Visual Basic 2010, and after experiencing a lot of things, i still wonder how can i add multiple header modifiers,
for instance i've added a mod to the Referer (yes with one r) which actually mods the site's referrer and stuff like that,

I want to know how to change other refs for the same site like user-agent and things like that. but all together for the same site,

This is the code

Dim HEADERS As String = "Referer:http://www.google.com/search?q=" + TextBox2.Text + "&oq=" + TextBox2.Text + "&aq=f" + Microsoft.VisualBasic.ControlChars.CrLf
Dim URL As String = TextBox1.Text
WebBrowser1.Navigate(URL, "_self", Nothing, HEADERS)

How am i supposed to add the user-agent change thing, for example next to the referer or something like that. do i need to create a new dim? how is it supposed to look like?
please assist me i will be waiting
Thanks
TT