yahoo smileys code!!

[batman]

hey guys,
how ru all!!

i was looking at c:\programfiles\yahoo\messenger\media\smileys folder and was just wondering how for example 1.gif or 25.gif are converted to relative smiley code and when we enter the code in yahoo msg we get the relative smiley.

is it some kind of encryption algorithm that yahoo uses or something else..

please reply

thanks!!