Well, just to add some info:

How do i link this QLineEdit to the array i have created?
Just type "QlineEdit" in the QT Assistant index and you will find all the info you could need. Take a look to "text()" and "insert ( const QString & newText )"


How do i use this button to write everything to the file?
You could use QFile to manage your files and (from Qt Assistant) "Data is usually read and written using QDataStream or QTextStream, but you can also call the QIODevice-inherited functions read(), readLine(), readAll(), write()."


But, of course, the most important is to read, read and read (and learn, learn and learn... and, in my case, ask in the forum, ask in the forum and ask in the forum :P)