private void btnLogin_Click(object sender, EventArgs e) { string userName = txtUserName.Text; string passWord = txtPassWord.Text; string passWordHash = Securities.CreateMD5(passWord); using (StoreManagementEntities ef = new StoreManagementEntities()) { foreach (var acc in ef.Account) { string usernameFromDB = acc.Username.Trim(); string passWordFromDB = acc.Password.Trim(); if (userName == usernameFromDB && passWordHash == passWordFromDB) { this.Hide(); FormMain frmMain = new FormMain(); frmMain.Show(); //MessageBox.Show("Login Successful.", "Infomation", MessageBoxButtons.OK, MessageBoxIcon.Information); notifyIconLogin.BalloonTipIcon = ToolTipIcon.Info; notifyIconLogin.BalloonTipTitle = "Infomation"; notifyIconLogin.BalloonTipText = "Login Successful"; notifyIconLogin.ShowBalloonTip(3000); return; } } MessageBox.Show("Please, Check username and password again.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } }