Or

This one is also a waste of time:

What buttons(exact buttons) are used for the OR function?
Because I don't know how to get the two small vertical lines!!

|| <----- I tried this(shift+button above enter) But I got a parse error,

Please help!

that's right, shift+backslash

post your code, maybe it's something else (don't forget code tags)

|| is a logic operator not a function. And post your code so we know what you are talking about...