How to delete inbox messages on facebook for iphone?

The problems that I'm having are… I have deleted messages on my laptop, yet they still show up on my phone. AND I've tried the swiping thing and I do NOT get a delete button. So please have other options besides swipe and delete button appears.

If it matters, I'm using 3gs and I should have the latest facebook update.

I'm not sure if this still works but the only way you can delete them is if you slid your finger to the lef.