What's the meaning of "to"

I’m a new applescript user. Reading the Applescript Language Guide (http://developer.apple.com/mac/library/documentation/AppleScript/Conceptual/AppleScriptLangGuide/conceptual/ASLR_script_objects.html#//apple_ref/doc/uid/TP40000983-CH207-SW2) I don’t understand exactly how to use “to” in statements like “to sayHello …”. I searched everywhere and found no formal definition. Is it like a user-defined command?


script John
property HowManyTimes : 0

to sayHello to someone
set HowManyTimes to HowManyTimes + 1
return "Hello " & someone
end sayHello

end script

tell John to sayHello to “Herb” --result: “Hello Herb”

Browser: Safari 531.22.7
Operating System: Mac OS X (10.6)


in this case to is a synonym for on, the keyword of a handler definition

Thanks Stefan