PDF generation

[Leila Cruickshank]

I downloaded Lilypond a few weeks ago and a friend successfully created 
several music files. I then tried to create one myself, but every time I 
generate the pdf, only one line of music appears as though the automatic line 
breaks have been overridden. This line continues off the side of the page and 
disappears. I continued to read the manual to find out what I'd done wrong, 
but it suggests it should automatically create a line break, and the ones my 
friend had done were fine. She could not suggest anything, and although I 
tried copying her file and just changing the notes and key, the same problem 
continued to occur. I tried the manual line break function but the error log 
informed me that something had overridden it. I then uninstalled Lilypond and 
reinstalled it, but to no avail. I need this music urgently for a project that 
is due very soon, and have no further ideas on how to correct it, any 
suggestions would be gratefully received!