previous data should not be append in my dropdownlist in asp.net 2005 with c#

[priyamsc]

hi, first i had the problem. tat is whenever i select the data it is added the previous value. so i have given [dd2.items.clear()]now its working but the problem is if it has only one value i cant select..so this is my problem... I have used 4 dropdownlist in tat if i select first dropdownlist then the based on the selectedvalue data will be bound in second dropdownlist but if it has only one value then i could not bound in next dropdownlist.i have written all the codings in dropdownlist_selectedindexchanged()... --------Select-------------- c# coding --------- dd3.Items.Clear(); string b = "select distinct a.descriptions,b.depid from Helpdesk_swift a,Helpdesk_pc_link b where a.swiftid='dep' and b.blockid=" + dd1.SelectedValue + " and b.locationid=" + dd2.SelectedValue + " and a.sid=b.depid"; SqlDataAdapter adp1 = new SqlDataAdapter(b, con); DataSet ds = new DataSet(); adp1.Fill(ds); dd3.DataSource = ds; dd3.DataTextField = "descriptions"; dd3.DataValueField = "depid"; dd3.DataBind(); so any one help me to do this....pls very urgent

k.priya