Delete Multiple Records From Gridview and also asking Permission to whether the record is delete or not

First Add this script to header tag on .aspx page:

  <script type="text/javascript" language="javascript">
        function DeleteConfirmation() {
            if (confirm("Are you sure, you want to delete selected records ?") == true)
                return true;
            else
                return false;
        }
    </script>


and call this function on button like this:

OnClientClick="return DeleteConfirmation()"

First Get the records from database attache to gridview

write the following code on button click event:

 string strID = string.Empty;

        for (int i = 0; i < gvsample.Rows.Count; i++)
        {
            CheckBox chkDelete = (CheckBox)gvsample.Rows[i].
                             Cells[0].FindControl("chkSelect");
            if (chkDelete != null)
            {
                if (chkDelete.Checked)
                {

                    Label lbldeleteid = (Label)gvsample.Rows[i].Cells[1].FindControl("lblid");
                    if (strID != string.Empty)
                        strID += ",";
                    strID += "" + lbldeleteid.Text + "";
                    //strID  = lbldeleteid.Text;
                    //idCollection.Add(strID);
                }
            }
        }
        string s1 = "delete from store where id in("+strID+")";
        //sb += sb.AppendFormat("{0}='{1}'; ", s1, item);
        con.Open();
        SqlCommand cmd = new SqlCommand(s1, con);
        //cmd.ExecuteNonQuery();
        int j = Convert.ToInt32(cmd.ExecuteNonQuery());
        con.Close();
        if (j > 0)
        {
            lblsample.Text = j+"Record(s) Deleted Sucessfully";
        }
        else
        {
        }
        getdata();