A joint continuity theorem

In this paper, we prove the following joint continuity theorem. Let $G$ be a locally countably compact regular $~F~$-group and let $X$ be a completely regular space such that $~X\times~X~$ is locally countably compact. Let $\pi\colon~G\times~X\rightarrow~X$ be an abstract group action. If the phase mapping $\pi$ is separately continuous, then $\pi$ is jointly continuous.