Let the camera decide.

Another event.  Another set of photographs.  Or, rather, another set of blur images.  While it's true that the colours turn out better if in a dimly lit environment with the flash off, without a steady camera, all you're going to get is a blur image.  Sure it looks good on the tiny LCD on the camera.  Blow it up on the monitor and it's irritatingly blur.  If all you have are your hands to position the camera, and the camera decides that flash is necessary, let it flash!