running script file in oracle

Please could anybody tell me where I should save my script file to in order to run it in oracle. I have tried saving it in Oracle directory, but error:

unable to open file accountUpdate.sql

hi,

open sqlplus

at prompt type

sql>@c:\test.sql

thanks for answering, but this does not work for me:

SP2-0310: unable to open file "bank.sql"

I have the file in c:

Any idea what I am doing wrong?