protected void Button3_Click(object sender, EventArgs e)
{
foreach (GridViewRow row in this.GridView1.Rows)
{
if (row.RowType == DataControlRowType.DataRow)
{
CheckBox ckb = row.Cells[0].FindControl("CheckBox1") as CheckBox;
if (ckb.Checked)
{
int i = Convert.ToInt32(row.Cells[1].Text);
string str = ConfigurationManager.ConnectionStrings["studentConnectionString"].ConnectionString;
using (SqlConnection cnn = new SqlConnection(str))
{
SqlCommand cmm = cnn.CreateCommand();
cmm.CommandText = "delete from student where protected void Button3_Click(object sender, Eve