IMacros formula Needed - If current URL matches a specific pattern, go back

While playing an existing iMacro file, most of the time I go to an unwanted specific URL on the same window. But, I want iMacros to identify the unwanted URL and make the browser go back.

My script

VERSION BUILD=8350307 RECORDER=CR
TAG POS=1 TYPE=A ATTR=TXT:Accept
TAG POS=2 TYPE=A ATTR=TXT:Accept
TAG POS=3 TYPE=A ATTR=TXT:Accept
TAG POS=4 TYPE=A ATTR=TXT:Accept
TAG POS=5 TYPE=A ATTR=TXT:Accept
TAG POS=6 TYPE=A ATTR=TXT:Accept
TAG POS=7 TYPE=A ATTR=TXT:Accept
TAG POS=8 TYPE=A ATTR=TXT:Accept
TAG POS=9 TYPE=A ATTR=TXT:Accept
TAG POS=10 TYPE=A ATTR=TXT:Accept
// I want add a script on if the current URL is "/error", then the browser should go back
WAIT SECONDS=2
TAG POS=1 TYPE=A ATTR=TXT:Next<SP>>
WAIT SECONDS=2