Entropy function for non-extremal black holes in string theory

We generalize the entropy function formalism to five-dimensional and four-dimensional non-extremal black holes in string theory. In the near horizon limit, these black holes have BTZ metric as part of the spacetime geometry. It is shown that the entropy function formalism also works very well for these non-extremal blak holes and it can reproduce the Bekenstein-hawking entropy of these black holes in ten dimensions and lower dimensions.