Auto flash not working in C1/C2/C3

Is there a way to enable it to work automatically?

No, if you want the flash and are not in the green box mode, you have to raise the flash yourself. The flash will automatically go up if needed ONLY in the green box setting.

"No, if you want the flash and are not in the green box mode, you have to raise the flash yourself. The flash will automatically go up if needed ONLY in the green box setting."

I feel dumb asking this but how do you raise the flash on a Canon 40D

There is a small button right under the flash accessible by your left hand as you are shooting. When you press it, it will make a whirring sound and the flash will pop up.

Thanks!!!