Why can't I delete photos on my iPad, some of my photos don't have a delete button is it because they have come from my computer?

If it was synced from your computer then it can't be deleted directly on the iPad, you will need remove/de-select it from where you synced it from on your computer and re-sync.

http://support.apple.com/kb/HT4236

The links below have instructions for deleting photos.

iOS and iPod: Syncing photos using iTunes

http://support.apple.com/kb/HT4236

iPad Tip: How to Delete Photos from Your iPad in the Photos App

http://ipadacademy.com/2011/08/ipad-tip-how-to-delete-photos-from-your-ipad-in-t he-photos-app

Another Way to Quickly Delete Photos from Your iPad (Mac Only)

http://ipadacademy.com/2011/09/another-way-to-quickly-delete-photos-from-your-ip ad-mac-only

How to Delete Photos from iPad

http://www.wondershare.com/apple-idevice/how-to-delete-photos-from-ipad.html

How to: Batch Delete Photos on the iPad

http://www.lifeisaprayer.com/blog/2010/how-batch-delete-photos-ipad

(With iOS 5.1, use 2 fingers)

How to Delete Photos from iCloud’s Photo Stream

http://www.cultofmac.com/124235/how-to-delete-photos-from-iclouds-photo-stream/

 Cheers, Tom 😉