dropdownlist onselectedindexchanged event is not working

Question

on page load the country dropdownlist is bind and working fine but after when i select the country than no state bind in state dropdownlist. 

 

 ----------------------front end-----------------------------

<asp:DropDownList ID="ddlcountry" runat="server" OnSelectedIndexChanged="ddlcountry_SelectedIndexChanged" AutoPostBack="true" CssClass="form-control ddl"></asp:DropDownList>

 

<asp:DropDownList ID="ddlstate" runat="server" AutoPostBack="true" CssClass="form-control ddl"></asp:DropDownList> 

 

--------------------------------code behind------------------------------ 

 

protected void Page_Load(object sender, EventArgs e)

{

if (con.State == ConnectionState.Closed)

{

con.Open();

}

if (!Page.IsPostBack)

{

getcountry();

}

}

protected void getcountry()

{

try

{

da = new SqlDataAdapter("select * from get_country", con);

ds = new DataSet();

da.Fill(ds);

ddlcountry.DataSource = ds;

ddlcountry.DataTextField = "conname";

ddlcountry.DataValueField = "conid";

ddlcountry.DataBind();

ddlcountry.Items.Insert(0, new ListItem("--Select--", "0"));

ddlstate.Items.Insert(0, new ListItem("--Select--", "0"));

}

catch (Exception ex)

{

Response.Write("error occurd :" + ex.Message.ToString());

}

finally

{

con.Close();

}

}

protected void ddlcountry_SelectedIndexChanged(object sender, EventArgs e)

{

try

{

int conid = Convert.ToInt32(ddlcountry.SelectedItem.Value.ToString());

da = new SqlDataAdapter("select stateid,statename from get_state where conid=" + conid, con);

ds = new DataSet();

da.Fill(ds);

ddlstate.DataSource = ds;

ddlstate.DataTextField = "statename";

ddlstate.DataValueField = "stateid";

ddlstate.DataBind();

ddlstate.Items.Insert(0, new ListItem("---Select State---", "0"));

if (ddlstate.SelectedValue == "0")

{

ddlcity.Items.Clear();

ddlcity.Items.Insert(0,new ListItem("---Select City---","0"));

}

}

catch(Exception ex)

{

Response.Write("error occurd :" + ex.Message.ToString());

}

finally

{

con.Close();

}

}