Keeping javascript functions when using CKEditor

I've searched the forums and documentation and have been unable to find an answer to this question:

The textarea boxes that I want to use CKEditor with currently have javascript functions which trigger off of the onfocus event. When I add CKEditor, those javascript functions appear to be replaced as they no longer trigger. Is there a way to keep those in place so that I can use CKEditor in the form?

Any assistance would be very appreciated, thank you!