Hi,
I am creating a cookie using the following code:
                Dim iharyanacookie As HttpCookie
                iharyanacookie = New HttpCookie("username", uid.Text)
                Response.Cookies.Add(iharyanacookie)

 But how can I delete or destroy a cookies. I using the following code about cookies is still there and working.
        Response.Cookies("iharyanacookie").Expires = DateTime.Now.AddYears(-30)
        Response.Cookies.Remove("iharyanacookie")
        Response.Redirect("http://www.iharyana.com")

Basically the whole page code is:

Imports System.Data.SqlClient

Partial Class WebUserControl
    Inherits System.Web.UI.UserControl

 Login Button:

  Protected Sub login_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles login.Click
        login_error.Text = ""
        Dim conn1 As SqlConnection
        Dim comm1 As SqlCommand
        Dim reader1 As SqlDataReader
        Dim connstring1 As String

        connstring1 = ConfigurationManager.ConnectionStrings("iharyana").ConnectionString

        conn1 = New SqlConnection(connstring1)

        Dim users As String
        users = "select password from usermain where username = @username"

        comm1 = New SqlCommand(users, conn1)

        comm1.Parameters.Add("@username", Data.SqlDbType.VarChar, 20)
        comm1.Parameters("@username").Value = uid.Text

        conn1.Open()

        reader1 = comm1.ExecuteReader

        If reader1.Read Then
            Dim pass As String
            pass = reader1.Item("password")
            If (pass = password.Text) Then
                'create cookies
                Dim iharyanacookie As HttpCookie
                iharyanacookie = New HttpCookie("username", uid.Text)
                Response.Cookies.Add(iharyanacookie)
                Response.Redirect("http://www.iharyana.com")

            Else
                login_error.Text = "Invalid Login ID or Password! Try Again"
            End If

        End If

        reader1.Close()
        conn1.Close()

    End Sub

Page Load:

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim iharyanacookie As HttpCookie
        iharyanacookie = Request.Cookies("username")
        If iharyanacookie Is Nothing Then

        Else
            user.Text = "Welcome back <b>" & iharyanacookie.Value & "</b>"
            uid.Visible = False
            pass.Visible = False
            password.Visible = False
            login.Visible = False
            forgot.Visible = False
            sep.Visible = False
            reg.Visible = False
            my.Visible = True
            logout.Visible = True

        End If
    End Sub

Logout Button:

    Protected Sub logout_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles logout.Click
        Response.Cookies("iharyanacookie").Expires = DateTime.Now.AddYears(-30)
        Response.Cookies.Remove("iharyanacookie")
        Response.Redirect("http://www.iharyana.com")

    End Sub
End Class

 Pls pls help.

 

hi boy,

Logout Button:

    Protected Sub logout_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles logout.Click
        Response.Cookies("iharyanacookie").Expires = DateTime.Now.AddYears(-30)
        Response.Cookies.Remove("iharyanacookie")

         Request.Cookies("iharyanacookie").Expires = DateTime.Now.AddYears(-30)
        Request.Cookies.Remove("iharyanacookie")
        Response.Redirect("http://www.iharyana.com")

    End Sub
End Class

hi,

Deleting Cookies

Dim aCookie As HttpCookie
Dim i As Integer
Dim cookieName As String
Dim limit As Integer = Request.Cookies.Count - 1
For i = 0 To limit
    cookieName = Request.Cookies(i).Name
    aCookie = New HttpCookie(cookieName)
    aCookie.Expires = DateTime.Now.AddDays(-1)
    Response.Cookies.Add(aCookie)
Next

check this url regarding cookies,

http://msdn2.microsoft.com/en-us/library/ms178194.aspx 

Hi ivanatanasov,

 It is showing following error:

Server Error in '/' Application.

---

Object reference not set to an instance of an object.

Line 72:         Response.Cookies.Remove("iharyanacookie")
Line 73: 
Line 74:         Request.Cookies("iharyanacookie").Expires = DateTime.Now.AddYears(-30)
Line 75:         Request.Cookies.Remove("iharyanacookie")
Line 76:         Response.Redirect("http://www.iharyana.com")

[NullReferenceException: Object reference not set to an instance of an object.]
   WebUserControl.logout_Click(Object sender, EventArgs e) in d:\hosting\satender88\login.ascx.vb:74
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102

Hi.

This works:

        Dim iharyanacookie As HttpCookie
        iharyanacookie = New HttpCookie("username", "abc")
        iharyanacookie.Expires = DateTime.Now.AddYears(-30)
        Response.Cookies.Add(iharyanacookie)
        Response.Redirect("http://www.iharyana.com")

Thanks gopalanmani, thanks a ton

 Hi,

Thanks for all your help i just have one suggestion that without creating a new cookie with same name we can also take instance of already existing cookie[As we are going to delete a cookie so it must  exist :)] and then set its expires date and set it back in response...for PoC i have created one static function which you can use by just passing the cookie name to delete. Here it is :  

        /// <summary>
        /// This function will be used to remove
        /// cookies value
        /// </summary>
        /// <param name="key"></param>
        /// <returns>Cookies value</returns>
        public static void RemoveCookie(string key)
        {
            //get cookies value
            HttpCookie cookie = null;
            if (HttpContext.Current.Request.Cookies[key] != null)
            {
                cookie = HttpContext.Current.Request.Cookies[key];
                //You can't directly delte cookie you should
                //set its expiry date to earlier date
                cookie.Expires = DateTime.Now.AddDays(-1);
                HttpContext.Current.Response.Cookies.Add(cookie);
            }
            
        }

here is the code to create the cookie & delete it...

                        //Create Cookie
                        HttpCookie aCookie = new HttpCookie("AdminInfo");
                        aCookie.Values["userName"] = txtUsername.Text;
                        aCookie.Values["Password"] = txtPassword.Text;
                        aCookie.Values["lastVisit"] = DateTime.Now.ToString();
                        aCookie.Expires = DateTime.Now.AddDays(10);
                        Response.Cookies.Add(aCookie);
                 
                        //Delete Cookie
                        HttpCookie aCookie = new HttpCookie("AdminInfo");                        
                        aCookie.Expires = DateTime.Now.AddDays(-1);
                        Response.Cookies.Add(aCookie);
                  

Hope this will help u..