how to insert item in list box from oracle database

i am new to asp .net . i have created a table in oracle having 2 columns one is for department name and the other is da name of the students . In the asp.net design page i ahve the drop down list where the name of different departments are given( in my case computer, electronics and electrical). i want a code such that when i click on a particular department say electrical then in the list box i get the name of all the students who belong to electrical department . I am unable to do it. i wrote this code but it isnt working..

 protected void drpdwndept_SelectedIndexChanged(object sender, EventArgs e)
    {
        Class1 ford = new Class1();

        int i,k;
      String sql = "select Department,Name from Result";
      
    OracleDataAdapter da = new OracleDataAdapter(sql, ford.ConnectionString);
      DataTable dt = new DataTable();
      da.Fill(dt);
        for(i=0;i<dt.Rows.Count;i++)
        {
            if(drpdwndept.SelectedItem.Text==dt.Rows[i][0].ToString())
            {
                k=i;
                lstboxstudents.Items.Add (dt.Rows[k][1].ToString());
                
                
            }
        }
        

See if this helps: http://forums.asp.net/t/1431726.aspx/1