Icao information input code

Hope we are posting this to the right board. We need to accept flight information from end users and have that converted to icao format (the same way as it occurs through the search bar on the flightaware.com site). Is there a reference or code snippet available to implement that so we can assure our users are entering useful information?

Thanks and apologies for a nube question
T

Are you looking for something that provides you with all the airlines and the ICAO codes or something that enforces the use of ICAO codes?

Anything that will allow us to force a users flight information input into icao format (same use case as entering an address into google and it forces the user to choose the right format as an option). Thanks for the response and help.

We do not have anything that provides a reference or suggests an option. This would have to be coded on your side. We do accept IATA codes for many of the calls. What call are you using?