Type-ahead using a value list only functions from the start of the text. However, you can implement a search such as you suggest using an OnKeystroke trigger and a global field. Basically, you fire the script on each keystroke to perform a search in a list view. You capture the value in the global field, perform the search, and put the cursor back in the search field.
A refinement of the technique, suggested by Jeremy Bante, involves using an OnTimer trigger to improve performance. This refinement involves firing the OnTimer script instead of the search script on each keystroke, only performing the search if the timer times out. This will prevent the search delay after each keystroke, because it will only perform the search when the user pauses his typing.
Thank you for your response...tis much appreciated.
I'll get straight onto Google now to get further informaiton on the two options you propose, to see if I can figure out how to use them (eeek).