dropdownlist selected index changed?

protected void ddlemployeeno_SelectedIndexChanged(object sender, EventArgs e)
    {
        ddlemployeename.Items.Clear();
        //Fetch the records for all the employeename & employeeno  in dataset
        DataRow[] drEmployeeName = dsemployeeno.Tables[0].Select("EmployeeNo='" + ddlemployeeno.SelectedValue.ToString() + "'");
        foreach (DataRow drrow in drEmployeeName)
        {
            ddlemployeename.Items.Add(new ListItem(drrow["name_of_column"].ToString(), drrow["name_of_column"].ToString()));
        }
        ddlemployeename.Items.Insert(0,new ListItem("-Select-"));

    }

protected void ddlStateCode_SelectedIndexChanged(object sender, EventArgs e)
    {
              string  strStateCode ="";
              strStateCode = ddl1.SelectedValue;
             // now u should send this value to database and get records according to this value and bind second dropdown with record 
            DataSet dsCity= new DataSet();
            dsCity= obj.fnGetDetails("strStateCode");// Get city details according to state code
            ddlCity.DataSource = dsCity.Tables[1];
            ddlCity.DataValueField = "Code";
            ddlCity.DataTextField = "Description";

            ddlCity.DataBind();
            ddlCity.Items.Insert(0, new ListItem("---Select City---", "0"));
  
                      
     }