Invalid object name 'RegMember'

public class DB
{
    SqlConnection conn;
    SqlCommand com;
    DataTable TB = new DataTable();
    private void Initialize(CommandType CT, string DBCall)
    {
        conn = new SqlConnection();
        com = new SqlCommand();
        conn.ConnectionString = ConfigurationManager.ConnectionStrings[1].ToString();
        com.CommandType = CT;
        com.Connection = conn;
        com.CommandText = DBCall;
        conn.Open();
    }
 public DataTable RunQuery(string SelectQ)
    {
        Initialize(CommandType.Text, SelectQ);
     
        TB = new DataTable();
        TB.Load(com.ExecuteReader());
        return TB;  
    }

public bool Login(string UserN, string Pass)
    {
        string query = string.Format("Select * From [RegMember] Where UserName='{0}' and Password='{1}' ", UserN, Pass);
        if (db.RunQuery(query).Rows.Count == 1)
            return true;
        else
            return false;
    }


protected void Btnlogin_Click(object sender, EventArgs e)
    {
        RegMember member = new RegMember();
        if (member.Login(TxtName.Text, TxtPasss.Text))
            LblMessage.Text = "User ,Ok";
        else
            LblMessage.Text = "username or pass incorrect";
    }