Return Parameters From Function

internal static void GetUserData(int userId, out string userName,
out string userEmail, out string userPassword)
{
using (SqlConnection con = Util.GetConnection())
{
con.Open();
using (SqlCommand cmd = new SqlCommand("usp_UD_SelectById", con))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("@UD_ID", SqlDbType.Int).Value = userId;
cmd.Parameters.Add("@UD_UserName", SqlDbType.NVarChar, 100).Direction = ParameterDirection.Output;
cmd.Parameters.Add("@UD_Password", SqlDbType.NVarChar, 100).Direction = ParameterDirection.Output;
cmd.Parameters.Add("@UD_Email", SqlDbType.NVarChar, 100).Direction = ParameterDirection.Output;
cmd.ExecuteNonQuery();
userName = Convert.ToString(cmd.Parameters["@UD_UserName"].Value);
userEmail = Convert.ToString(cmd.Parameters["@UD_Email"].Value);
userPassword = Convert.ToString(cmd.Parameters["@UD_Password"].Value);
}
}
}

and the call

string userEmail;
string userName;
string userPassword;
MemberHelper.GetUserData(userId, out userName, out userEmail, out userPassword);

Sometimes I need to get just one parameter from the out parameters, how can I call the function when I want to get just one:

string userPassword;
MemberHelper.GetUserData(userId,"","",out userPassword);