Dropdown list related

Question

Hi,
   I am using a dropdown list it holds around 1000 items, while selecting a particular item ,means i should scroll and search the item, it is very difficult to do this. so now what i want is if i enter a number like 17 means the numbers starting with 17 series should show for example if i enter 17 the next series numbers are 17889,17865,17564,17786,17483,17894,17569 and so on should show automatically from these numbers i can select any number i needed. how to do this using asp.net. please can anybody help me regarding this? thanks in advance.