Error in select statement - no value given for a parameter

string str = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\inetpub\wwwroot\myfolder\mydatabase";

string password = "";

string accountemail = "";

using (OleDbConnection con = new OleDbConnection(str))

{

using (OleDbCommand cmd = con.CreateCommand())

{

cmd.CommandText = "SELECT password, email FROM [users] WHERE username = @user";

cmd.Parameters.Add("@user", OleDbType.VarChar).Value = Request.Form["username"];

con.Open();

using (OleDbDataReader reader = cmd.ExecuteReader())

{

while (reader.Read())

{

password = reader["password"].ToString();

accountemail = reader["email"].ToString();

}

//reader.Close();

}

//con.Close();

}

}

string fromaddress = "myemail"; //send from admin/mail server

string toaddress = accountemail; //send to respective user

string subject = "forgot password";

string body = String.Concat("This is the password that you have requested: ", password, ". Please do not reply, this is an automated email."); //content of the email

try

{

var fromAddress = new MailAddress(fromaddress);

MailMessage mail = new MailMessage();

SmtpClient smtp = new SmtpClient();

MailAddressCollection m = new MailAddressCollection();

m.Add(toaddress);

mail.Subject = subject;

mail.From = new MailAddress(fromaddress);

mail.Body = body;

mail.IsBodyHtml = true;

mail.ReplyToList.Add(fromAddress);

mail.To.Add(m[0]);

smtp.Host = "smtp.gmail.com";

smtp.Port = 587;

smtp.EnableSsl = true;

smtp.Credentials = new System.Net.NetworkCredential(fromaddress, "mypassword");

ServicePointManager.ServerCertificateValidationCallback = delegate(object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; };

smtp.Send(mail);

MessageBox.Show("Success, your password has been sent to you.");

}

catch (Exception ex)

{

Response.Write(ex.Message);

Response.Redirect("Login.aspx", false);

}

}