How Can I Search A Select Tag With JavaScript

Does any of you know how to create a drop-down list that allows the user to search the drop-down list using two characters, that is, the user will click on two characters of the keyboard which will be the first two characters of the word they are searching for in the list, which will be match to the first two characters of the the first word that has those two characters first.
For instance, we are use to searching in a drop-down list using one character which matches to the first letter of the word first word in the list in alphabetic order.

Now, what I am looking for is to search with two characters; which will match with the first two letters of the words in the list in alphabetic order.