How solve this error (The name 'LinkButton1' does not exist in the current context) in masterpage?

public partial class MasterPage : System.Web.UI.MasterPage
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Session["login"] != null)
        {

            lbllogin.Text = "Welcome" + Session["login"].ToString();
            lbllogin.Visible = true;
            LinkButton1.Text = "logout";

        }
        else
        {
            lbllogin.Visible = false;
            LinkButton1.Text = "login";
        }
    }
    protected void LinkButton1_Click(object sender, EventArgs e)
    {
        if (LinkButton1.Text == "login")
        {
            Response.Redirect("~/login.aspx");
        }
        else
        {
            Session.Clear();
            Response.Redirect("~/home.aspx");
        }
    }
}