private void login_btn_Click(object sender, EventArgs e)
 {
     if (onlineUserType != null)
     {
         OrclDatabase.SignInUser(username_txt.Text, password_txt.Text, onlineUserType);
     }
     else
     {
         MessageBox.Show("Select User type first", "Check Credentials", MessageBoxButtons.OK, MessageBoxIcon.Warning);
     }
 }