stored procedure problem

I use the following stored procedure to verify that a username doesn't exst before creating another with the same name.
CREATE PROCEDURE AddUniqueUser
(
@userID nVarChar(50),
@password nVarChar(50),
@dateAdded smallDateTime
)
AS
If Exists
(
SELECT userID
FROM Users
WHERE userID = @userID
)
RETURN 1
ELSE
INSERT Users ( userID, password, dateAdded )
VALUES ( @userID, @password, @dateAdded )
RETURN
@@identity
GO
2 Lines up you see--
RETURN
@@identity
That kicks back the newly created 'accountNum'
I'm using this--
Dim connStr As SqlConnection
Dim cmdAddUniqueUser As SqlCommand
Dim paramReturnValue As SqlParameter
Dim paramReturnValue2 As SqlParameter
Dim dateAdded As DateTime
dateAdded = DateTime.Now()
Dim accountNum As Integer
connStr = New SqlConnection(ConfigurationSettings.AppSettings("sqlCon.ConnectionString"))
cmdAddUniqueUser = New SqlCommand("AddUniqueUser", connStr)
cmdAddUniqueUser.CommandType = CommandType.StoredProcedure
paramReturnValue = cmdAddUniqueUser.Parameters.Add("ReturnValue", SqlDbType.Int)
paramReturnValue.Direction = ParameterDirection.ReturnValue
cmdAddUniqueUser.Parameters.Add("@userID", txtUserName.Text)
cmdAddUniqueUser.Parameters.Add("@password", txtPassword1.Text)
cmdAddUniqueUser.Parameters.Add("@dateAdded", dateAdded)
connStr.Open()
cmdAddUniqueUser.ExecuteNonQuery()
If cmdAddUniqueUser.Parameters("ReturnValue").Value = 1 Then
Me.lblUserExists.Visible = True
Me.lblUserExists.Text = "UserName already exists. Please try again."
Else
Response.Redirect("newUser2.aspx?aNum= I need accountNum here
End If
connStr.Close()
Everything works fine, but I need to use the 'accountNum' in my Response.Redirect. Please, if anyone knows how to get this done let me know. I tried adding another 'paramReturnValue' and calling it 'paramReturnValue2' but all I got was '0' which was returned because I was submitting a new userID.