combo box help needed!

Dear all,
I am not sure if this is the best place for this question but it is my first time here so I am sorry if I am wrong.

I am new to VB but old in programming, as a mater of fact i am new to windows application since until now i was only working on dos applications.
Anyway i am trying to learn VB .net the best possible way, with a couple of books and a nice program i want to create. I have created a combo box and after some time of trying i have managed to insert the names of the worksheets from an excel file, that was quite hard since i had no idea what to use. After that though i thought that it would be a good idea to add something extra, like this thing that completes the sentence by just entering the few first letters. You know like pressing "T" and the combo box gives you "Tek-tips".
Do you have any idea how to do this? and what is the name of such a thing so i can search for it?
Thank you Ilias Skaros.

Perhaps you can use the combobox's TextChanged event and use its .FindStringExact method to get an index for the first item that matches the "T". The result that you get from .FindStringExact(.Text), you can assign that to the .SelectedIndex property of the combo box :).