private void button1_Click(object sender, EventArgs e)
    {
        SqlConnection log = new SqlConnection("Data Source=MODIFIEDforStackOverflow;Initial Catalog=logininfo;Integrated Security=True;Connect Timeout=15;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False");

        log.Open();

        string newcon=("select username from login where username='"+textBox1.Text+"' and password='"+textBox2.Text+"'");

        SqlDataAdapter adp = new SqlDataAdapter(newcon, log);

        DataSet ds = new DataSet();

        adp.Fill(ds);

        DataTable dt = ds.Tables[0];

        if (dt.Rows.Count >= 1)
        {
            settext = textBox1.Text;

            welcome wc = new welcome();
            wc.Show();

            this.Hide();
        }else
        {
            label3.Text = "Invalid Login!";
        }
    }