My actionscript code has been replaced by another language

I have been working on a script for weeks now and had a problem saving the file so i tried saving it to another location when i re-opened the file my actionscript code which was in english has gone and been replaced by what looks like is chinese or korean ??? is there anyway that could have happened and can i reverse it back??
Unfortunately i dont have a previously saved version so im stuck!!
any help would be so appreciated

I have looked and seen if there is anyway i could have accidently done this but cannot figure it out Please help???