Is this phrase right?

I'm developing an application in English, but I'm not a native English speaker. The following message will appear when my program is processing so users have to wait until the process ends.

"now processing..don't terminate this program"

I don't know if the phrase开发者_Python百科 is used the right way in English. Can anyone help?

Thanks.

---

I've always been a fan of "Processing, please wait".

A progress bar or some other visual indicator can also help ensure your users wait while giving them something to look at while they are waiting.