Nikon D40 flash doesn't pop up?

Our nikon d40 flash won't pop up. The battery is full. I switch to any modes but the flash doesn't work. Could somebody help me to fix this problem.

Look for a lighting bolt symbol and push it to see if it's on or off. It also depends what setting you have it on some setting turn it off or on check the manual or google nikon d40 manual and download the PDF file

After pressing the flash-up button, use your finger nail to prod it open. The spring may already be weak (it's an old camera) or dirt may be preventing it from going up.