I'm not quite sure what you are trying to do - which tends to mean that nor are you.

You might want to rephrase the problem into pseudo code, something like this:

#for each line {
#  split line into bits;
#  has string been seen {
#    do something;
#  }
#}
[download]

If you get this bit right then you can turn the pseudo code into real code fairly easily. It will also hep you keep track of what you are doing. I recall being a beginner and how easy it was getting lost in even a short bit of code. This technique I found very helpful.

If you are still stuck then post back the pseudo-code and someone will probably help you fill it. However without the pseudo code it is difficult to know exactly what you want to achieve...

--tidiness is the memory loss of environmental mnemonics