C#

Open And Close Connection Every Execution

Open Connection Only One Time

<form id="login_form" action="" method="post">
     <label>Email:</label>
     <label>Password:</label>
     <input type="text" name="login_email" id="login_email" />
     <input type="password" name="login_password" id="login_password" />
     <button id="login_button" type="submit">Login</button>
     <a href="#">¿Forgot password?</a>                
</form>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Sql;
using System.Data.SqlClient;

public partial class login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        
    }

    private void login_button(object sender, EventArgs e)
    {

        SqlConnection connection = new SqlConnection();
        connection.ConnectionString = "Server=(local)\\SQLEXPRESS;" + "user ID=myuser; Password=mypassword;" + "Database=mydatabase";

        try
        {
            connection.Open();
           
        }
        catch (Exception)
        {
           //Not connecting
        }

        
    }
}

private AutoResetEvent ar;
        private WebBrowser brs;

        [STAThread]
        private void Contribute_Load(object sender, EventArgs e)
        {
            ar = new AutoResetEvent(false);
            brs = new WebBrowser();
            brs.Url = new Uri("http://www.gmail.com");
            brs.Navigated +=new WebBrowserNavigatedEventHandler(brs_Navigated);
            ar.WaitOne();
            Console.WriteLine("Navigated to gmail.com");
        }

        void brs_Navigated(object sender, WebBrowserNavigatedEventArgs e)
        {
            ar.Set();
        }