Retrieves the default user name, or the user name used to establish a connection
_WinNet_GetUser ( $sName )
|$sName||Either the name of a local device that has been redirected to a network resource, or the remote
name of a network resource to which a connection has been made without redirecting a local device.
If blank, the system returns the name of the current user for the process.
|Success:||the user name.|
|Failure:||sets the @error flag to non-zero.|
Search WNetGetUser in MSDN Library.