Help with iPad app

[karinds]

Hi guys,
I need help with using the iPad app. I select my pen tool to draw straight lines but cannot get it to let go so I can alter the line as a score line. When I draw the line and then select the pointer tool the lines disappears. What am I doing wrong? If I can't get this to work then this app is a total waste of money.
Cheers
Karin