Unloading a textfile completely before loading next one

1

In have an application that uses buttons t0 load different text files. The problem is when I load the second text file I still get variables from the first one showing. To clarify things, suppose I load a file that displays variables 1 through 5 randomly when I click one button, then I click a second button in order to load a file that displays 6 through 10. The problem is that I still get some variables from 1-5 when I want to get only 6-10. Is the first file kept in memory or something? How do I unload or clear the temp/memory where the content of the first file is held. I hope this one turns to be a small problem.