plz correct the bellow cod for entering datas from a asp.net form to database table.....

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
public partial class user_onlinepatientregistration : System.Web.UI.Page
{
    Class1 ob = new Class1();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {


            bindcountry();
            // clear();

        }
    }
    void clear()
    {
        bindcountry();
        bind_state();
        bind_city();
        pn.Text = "";
        age.Text = "";
        pq.Text = "";
        pno.Text = "";
        email.Text = "";
        add.Text = "";

    }


    public void bindcountry()
    {
        ob.fetch("select * from admin_country order by countryid");
        drdcon.Items.Clear();
        drdcon.DataSource = ob.ds.Tables[0];
        drdcon.DataTextField = "countryname";
        drdcon.DataBind();
        drdcon.Items.Insert(0, "select");
    }
    protected void btnsubmit_Click(object sender, EventArgs e)
    {
        if (pn.Text.Trim() == "")
        {
            lblmsgpn.Text = "name should not blank";
            pn.Focus();
            return;
        }
        if (pq.Text.Trim() == "")
        {
            lblmsgpq.Text = "patient query should not be blank";
            pq.Focus();
            return;
        }
        if (email.Text.Trim() == "")
        {
            lblmsgemail.Text = "Email Id should not be blank";
            email.Focus();
            return;
        }
        if (pno.Text.Trim() == "")
        {
            lblmsgpno.Text = "Mobile should not be blank";
            pno.Focus();
            return;
        }
        if (drdcon.SelectedIndex == 0)
        {
            lblmsgcon.Text = "Country name most be selected";
            drdcon.Focus();
            return;
        }
        if (drdst.SelectedIndex == 0)
        {
            lblmsgst.Text = "State  name most be selected";
            drdst.Focus();
            return;
        }
        if (drdge.SelectedIndex == 0)
        {
            lblmsgage.Text = "Security question must be selected";
            drdge.Focus();
            return;
        }

        if (drddept.SelectedIndex == 0)
        {
            lblmsgdept.Text = "Security question must be selected";
            drddept.Focus();
            return;
        }

        if (drddoctor.Text.Trim() == "")
        {
            lblmsgdr.Text = "Answer should not be blank";
            drddoctor.Focus();
            return;
        }
        ob.fetch("select Email from onlinepatient_reg where Email='" + email.Text + "'");
        if (ob.ds.Tables[0].Rows.Count > 0)
        {
            lblmsgemail.Text = "Already Exists";
            email.Text = "";
            email.Focus();
            return;
        }
        else
        {
            if (ob.dml_statment("insert into onlinepatient_reg values('" + pn.Text.Trim() + "','" + drdge.Text.Trim() + "','" + age.Text.Trim() + "','" + pq.Text.Trim() + "';'" + drddept.Text.Trim() + "','" + drddoctor.Text.Trim() + "','" + pno.Text.Trim() + "','" + email.Text.Trim() + "','" + add.Text.Trim() + "','" + drdcon.SelectedItem.Text + "', '" + drdst.SelectedItem.Text + "','" + drdcit.SelectedItem.Text + "','" + "')") > 0)
            {
                Response.Write("<script LANGUAGE='JavaScript'>alert('Data Submitted Sucessfully')</script>");

                clear();
            }

        }
    }

    public void bind_state()
    {
        ob.fetch("select * from admin_state where country='" + drdcon.SelectedItem.Text + "'");
        drdst.Items.Clear();
        drdst.DataSource = ob.ds.Tables[0];
        drdst.DataTextField = "statename";
        drdst.DataBind();
        drdst.Items.Insert(0, "select");
    }

    protected void drdcon_SelectedIndexChanged(object sender, EventArgs e)
    {
        bind_state();
    }
    public void bind_city()
    {
        ob.fetch("select * from admin_city where state='" + drdst.SelectedItem.Text + "'");
        drdcit.Items.Clear();
        drdcit.DataSource = ob.ds.Tables[0];
        drdcit.DataTextField = "cityname";
        drdcit.DataBind();
        drdcit.Items.Insert(0, "select");
    }
    protected void drdst_SelectedIndexChanged(object sender, EventArgs e)
    {
        bind_city();
    }


    protected void Button2_Click(object sender, EventArgs e)
    {
        Response.Write("REGISTRATION SUCCESSFUL");
    }

    protected void Button3_Click(object sender, EventArgs e)
    {
        clear();
        drdcit.SelectedIndex = 0;
        email.Focus();
    }
}