you're obviously new to scripting

an alias called by $ will execute all the commands in an alias
the $ prefix is used incase you want to use evaluate something in a different alias and return something
hence why the first reply used $isid and the /return prefix
the BEST help file i've ever seen is the one written for mIRC
if you want to script i HIGHLY recommend you read it
and play with it
it was the best 3 hours i spent.
it dosnt take very long to read it
in your case i suggest you start with /help aliases
it explains the $ prefix, also how exactly aliases work