pls suggest query fo below code

SqlCommand cmd;
SqlDataReader dr;
private string s;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        ddlComplaint.Items.Insert(0, new ListItem("---Select---", "---Select---"));
        FillDropDownList();
        ddlAllow.Items.Insert(0, new ListItem("---Select---", "---Select---"));
        FillTechnicianDropDownList();
    }
}



// Fill Dropdownlist
public void FillDropDownList()
{
    s = WebConfigurationManager.ConnectionStrings["Callregister_connectionstring"].ConnectionString;
    con = new SqlConnection(s);
    con.Open();
    cmd = new SqlCommand("Select Complaint_no from Call_Reg where Status='Open'" , con);
    dr = cmd.ExecuteReader();
    while (dr.Read())
    {
        ddlComplaint.Items.Add(dr[0].ToString());
    }
    dr.Close();
    con.Close();
}

// Show data in GridView
protected void btnSearch_Click(object sender, EventArgs e)
{
    s = WebConfigurationManager.ConnectionStrings["Callregister_connectionstring"].ConnectionString;
    con = new SqlConnection(s);
    con.Open();
    cmd = new SqlCommand("Select * from Call_Reg where Complaint_no='" + ddlComplaint.SelectedItem.ToString() + "'", con);
    dr = cmd.ExecuteReader();
    GridView2.DataSource = dr;
    GridView2.DataBind();
    dr.Close();
    con.Close();
}

// Fill Technician
public void FillTechnicianDropDownList()
{
    s = WebConfigurationManager.ConnectionStrings["Callregister_connectionstring"].ConnectionString;
    con = new SqlConnection(s);
    con.Open();
    cmd = new SqlCommand("Select Fname from New_Tech", con);
    dr = cmd.ExecuteReader();
    while (dr.Read())
    {
        ddlAllow.Items.Add(dr[0].ToString());
    }
    dr.Close();
    con.Close();
}

protected void btnAllo_Click(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection("SERVER=KSHITIJA-PC; Initial Catalog=CRM;Integrated Security=True");
    //SqlCommand cmd = new SqlCommand("Update Call_reg set status='Assigned' Where Complaint_no= '" + ddlComplaint.SelectedItem.ToString() + "'", con);
    SqlCommand cmd = new SqlCommand(" insert into Call_Allocation values( "", con);
    try
    {
        con.Open();

        int i = cmd.ExecuteNonQuery();
        //int a = cmd1.ExecuteNonQuery();
        if (i  == 1)
        {
            ddlComplaint.SelectedItem.Text = "";
            EO.Web.MsgBoxButton mb = new EO.Web.MsgBoxButton("OK");
            MsgBox1.Show("Message: ", "Call Assigned to Technician", null, mb);
         }

    }
    catch (Exception ex)
    {
        EO.Web.MsgBoxButton mb = new EO.Web.MsgBoxButton("OK");
        MsgBox1.Show("Error: ", ex.Message, null, mb);

    }
    con.Close();
}