SQL column not found when using parameters.

Hello,

I have the code below to look up a user name.  I am trying to use parameters to strengthen against SQL injections.  When I run the code below, I get the error:  ERROR [42S22] [IBM][System i Access ODBC Driver][DB2 for i5/OS]SQL0206 - Column or global variable @INUSR not found. This happens on the command.executereader line. 

Any help as to what I am doing wrong would greatly be appreciated.

Thank you in advance.

		dim inName as string = "Roland"
		Dim querystring As String = "SELECT * FROM dbfile WHERE usertype = @inUSR"

            Using connection As New OdbcConnection(ConfigurationManager.ConnectionStrings("myConnection").ConnectionString)
                Dim command As New OdbcCommand(querystring, connection)
                command.Parameters.Add("@inUSR", System.Data.SqlDbType.Text).Value = Trim(inName)
                connection.Open()
                command.ExecuteReader()
                 reader.Read()
                Session("access") = reader("usracc")
            End Using