It's 'useless' trying to change her mind. = It's 'useless' to try to change her mind.
Drugs are 'useless' in treating the condition.
I made a 'useless' attempt at fixing the leak.
(..) I think so. Give me a kiss. Okay, Professor! Hang on there. I think I fixed it. I got it. Fuck me! This thing is useless! Sorry! Wait, wait! Good! Give me a reading! Okay, boss lady, hold your horses. Which way do you want it? (..)1996 Twister