how to grep error messages

[Soren Orel]

I can /dev/null the error messages like:

cd "$1" 2> /dev/null

e.g.: I get error If "$1" has spaces in it

Ok, but how can I grep the error message? I tried:

if cd "$1" 2> grep -i "No such file or directory"; then echo "badbadbad";
exit; fi

But it doesn't work :S

thank you!