Breding Dwarf Hamsters

Question
I have 2 dwarf hamsters. One is a femail which I have had for a few months, the other I bought recently. I wanted them to mate, and have done everything I can think of to get them used to each other. I put them in the same cage with a separater, I put one cage in a tub(one in teh tub, teh other in the cage whewre they could touch noses, 2 days later switched them, 2 days later put them in the tub and watched) and they fight. She runs after him and corners him, and he paws her. At first I though she was just trying to snif him, she wouldn't bite unless he hurt her, but when holding both of them, she jumped out of my hand and took a huge bite out of him. While in teh tub, I was told to put one in a container, like a glass and seperate them for a bit if fighting occured, butit just hapens again after I let her go. They spent last night sleeping in their huge food dish next to each other (I stayed up and watched them and my pregnet syrian) and they slepted all night just fine until abot 8:30 am, when they started again. Please advise. I need to know soon, so I can take him back if it doesn't work out. Thanks.

Answer
heya
apoligies for taking so long to answer the question, i went away and the site wouldn't let me change my status to away.
  Firstly, when introducing  hamsters its always important you put them in the males cage, otherwise the female will be territorial. you are going about introducing them in the right way though :-)
  all i can tell you to do is keep trying, it may be the the female is too old to be introduced to another male, becuase shes been on her own for so long. if they a fighting seriously they should be separated, but all animals play fight, ie if shes biting him hes squeaking with pain or bleeding its important you separate them.
i hope this helps.
~suz