Logging into a network via C#

[Benny Raymond]

I'm currently writing a time tracking app to replace the one we've had
on our intranet for quite some time. I'd like to set this up to
communicate with a server side asp page using xml data transfer to get
access to the database. The only problem I can see myself having while
coding this is that the current asp page requires a network login (a
network login prompt shows up when the users access the page). How can
I do this in C# windows app? Below is the line where I extract the
login information from the IIS server's required login:

====code====
'Get employee data
Dim sLogonId
testLogon = Request("xLogon Id")
if testLogon <> "" Then

sLogonId = Request("xLogon Id")
Else
'Dim sLogonId

sLogonId = Request.ServerV ariables("AUTH_ USER")
End if
====/code====

then I get information from the database using this login id (we store
the login id in the database):

====code====
sSql = "Select EmpId, FName, LName From Employees Where Status = 'A' and
NTLogon = '" & sLogonId & "'"
rs.Open sSql, cn, 1, 3
if Err.Number <> 0 Then HandleError("Fa iled to retrieve employee
information")

if rs.eof then
HandleError("Ac cess is denied because your account information
could not be authenticated." )
Else
====/code====

Obviously the last part can be done pretty easily, i'm just using the
sLogonId that I get from the server in one of these two lines:
sLogonId = Request("xLogon Id")
or
sLogonId = Request.ServerV ariables("AUTH_ USER")

I didn't write the asp code... someone in some other company wrote it
for us long ago. I just need to know how to reproduce this login
information in a C# windows app program... basically how do I log into a
network and get the login id (which is something like this:
WORKGROUPNAME\u sername