HELP please quickly

Here is a brief description of what I want to do. I want to use PHP to grab a list of numbers in one file. Check it against a bigger file and strip the ones that match out of the bigger file, into a "holding" file. so here is what it might look like. file1.txt 456789 456790 456791 456792 456793 456794 .... file2.log some time stamp code=001;number=456784;name=blahblah;date=012403; some time stamp code=001;number=456785;name=blahblah;date=012403; some time stamp code=001;number=456786;name=blahblah;date=012303; some time stamp code=001;number=456789;name=blahblah;date=012503; some time stamp code=001;number=456789;name=blahblah;date=012503; some time stamp code=001;number=456789;name=blahblah;date=012503; some time stamp code=001;number=456789;name=blahblah;date=012503; some time stamp code=001;number=456789;name=blahblah;date=012503; some time stamp code=001;number=456790;name=blahblah;date=012603; some time stamp code=001;number=456791;name=blahblah;date=012703; notice there might be more then one of the same number, I only need one so I need to ignore the rest, rip out the time stamp, which is a seperate line. file3.txt code=001;number=456789;name=blahblah;date=012503; code=001;number=456790;name=blahblah;date=012603; code=001;number=456791;name=blahblah;date=012703; can anyone help, any suggestions? _________________________________________________________________ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus