How to delete pictures on your iphone?

I synced my phone up to my itunes and all my pictures on my computer are now on my computer. How do i delete them?

Hit the delete button

Photo library photos, which are synced from your computer to your phone, must be removed by connecting your phone to iTunes, then going to the Photos tab of your iTunes sync settings, deselecting the folders you no longer want (or deselecting Sync Photos if you want to remove them all), then syncing your phone.

Uncheck sync photos from the iphone section that shows up when you press iphone from the sidebar.

You can only delete single pictures, or an album you have made yourself. If you want to delete a single picture, press the little trash can button under the pic. Or if you want to delete an album you have made, swipe to the left on the album.
When you are on itunes, when your phone is connected on the side bar it will show your phone in itunes.
Click on that and it will bring up all the contents on your phone eg, music pictures blah blah.
Go into the picture tab at the top, and you need to select the picture file your itunes is syncing the pictures from.
That's probably hard to grasp, but otherwise it will just keep syncing those photo's back into it.
Personally i hate iphones there to much trouble aha.