I'm trying to load four file
File1 contain 50 first name
File2 contain 50 last name
File3 contain 50 dpeartment
File4 contain 50 id number
I want to load these file
for example when the files load I want to generate (randomly) this output
id,first name,last name, department
but I don't want dublicate id or name

now you are talking about multithreading?
what do you mean by "loading"? uploading? reading txt files from your harddrive?

what have you tried so far, and what exactly is it that you are trying to achieve?