Asp.net - Handling Errors From HttpWebRequest.GetResponse?

I'm having a ridiculous time trying to get an SMS API working (ZeepMobile, if you're interested) with .NET... I've been around .NET for a few years, but with all this social networking and API stuff, I need to get into the HttpWebRequest a bit. I'm new at it, but not completely new; I was able to hook up my site to Twitter without too much fuss (ie, I was able to modify someone's code to work for me).

Anyways, the way their API works is to send an SMS message, you send them a POST and they respond back to you. I can send it just fine, but every time I do, rather than echo back something helpful to figure out what the error is, I get the Yellow Error Page Of Death (YEPOD) saying something to the effect of "The remote server returned an error: (400) Bad Request." This occurs on my line:

'...creation of httpwebrequest here...'
Dim myWebResponse As WebResponse
myWebResponse = request.GetResponse() '<--- error line

Is there any way to simply receive the error from the server rather than have the webserver throw an exception and give me the YEPOD?

EDIT: Here's my whole code block:

Public Shared Function SendTextMessage(ByVal username As String, _
ByVal txt As String) As String
Dim content As String = "user_id=" + _
username + "&body=" + Current.Server.UrlEncode(txt)

[code]....