Delete Record From Database OnClick

I have a form where users can subscribe and unsubcribe to my email list. so far, i have the subscribe button working fine "add member" function. Now i need help with my "delete member " function (unsubscribe button). it will allows the user to delete their record from the database. When I run the code and click the "unsubscribe" button, i can't get the logic correct so that it will delete the user's record if it exisit. here's the code i'm using for the subscribe and unsubscribe buttons

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class joinmailinglist : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void addMember(object sender, EventArgs e)
{
// here you are defining the classes for the database and the linq
mailinglistClassDataContext Class = new mailinglistClassDataContext();
mailinglistMember member = new mailinglistMember();
// Now we are going to add the data to the member
// Here we are going to let the system define a GUID for the unique user ID
member.memberID = new Guid();
// here we are going to capture the user inputs and we are going to set these to lower case especially the email so that we can do a proper comparison later.
member.fname = txtFirstName.Text;
member.lname = txtLastName.Text;
member.email = txtEmail.Text;
// Here we are going to create the URL so we can later remove the user if they decide to opt out.
member.removeurl = "http://removeuser.aspx?code=" + member.memberID.ToString();
// Here we are going to use a LINQ query to search the class of mailinglistmembers for any emails that contain equal values of the text field and select it. var duplicatecheck = from emails in Class.mailinglistMembers where emails.email.Contains(txtEmail.Text) select emails...............................