PHP - Reading a file but not locking it

Hi,

Im hoping someone can help me with a small problem im having.

I have a program which is logging actions from a windows application. This application puts actions into a text file which im reading and formatting to put into a database. All that is working fine.

But! When reading the log file with PHP if the program wants to add an action to that log file it says it cant create the log file, obviously because im reading it with php at that time.

Is there anyway I can read it but also allow the application to write to it no matter what. I can open the log file in notepad and the application will strill write to it.

Thanks for any help.
Martin