My Fish Keep On Fighting, Why?

Well a tank divider has holes so if you have a filter the warmth or cold will get through it

Sometimes fish will fight before they breed, but not to the extent that you are describing. It depends on the type of fish you have. Some fish will fight until one of them dies. You need to separate them so they will stop fighting. If you have another tank then you need to get it set up quick and break up the fighting fish. If you do not have another tank then you can purchase a tank divider from your pet store and put the divider in your tank to keep the fighting fish apart. Otherwise you can see if you have a friend with a tank that would be willing or a pet store that would be willing to take one of your fighters to break up the problem. If you have a cave ornament then put it in the tank so one of the fish might have the chance to hide from the stronger bully fish.

My fish keep on fighting too one of them has blood on it :S what do I do?

You net one out and punish it if this does not work separate them