the with() function

Should I be using this? or is it going to be leaved out of javascript?
I use it like so:

with(tooltip.style){
left=Xpos+"px";
top=Ypos+"px";
display="block";
}

and jslint says:
Expected an identifier and instead saw 'with'.
Is with() depricated or something?

btw, I tried searching mozilla.org, google and these forums, but it's hard since all of these search engines take out the word with because it is too common...

You shouldn't use the with() syntax anymore. It's deprecated and apparently costly for the interpretter. :)

ok, thank you, that's what I wanted to know :)