Hi there
Here are a couple of links from this forum that may very well help you along with these questions.
A)
http://www.silkysteps.com/forum/showthread.php?t=13986
B)
http://www.silkysteps.com/forum/showthread.php?t=15242
A,B AND C)
http://www.silkysteps.com/forum/showthread.php?t=13238
Hope they give you some idea of how to get your head around them.
good luck.