OForgotPass.aspx.cs

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

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

    }
   
    protected void Button1_Click1(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["db"].ConnectionString);
        con.Open();
        SqlCommand cmd = new SqlCommand("select * from GuestInfo where MobileNo =@username ", con);
        cmd.Parameters.AddWithValue("@username", Email1.Text);
       
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();

        da.Fill(dt);

      if (dt.Rows.Count > 0)
        {
            Session["MN"] = Email1.Text;
                Response.Redirect("ResetPass.aspx");
        }
        else
        {
            ClientScript.RegisterStartupScript(Page.GetType(), "validation", "<script language='javascript'>alert('Invalid MobileNo>");
        }



    }
}