when I try to upgrade the ios software on my ipod touch 4 g flashes Apple . Heip me please!

See Here > http://support.apple.com/kb/HT1808

You may need to try this More than Once...

Be sure to Follow ALL the Steps...

But... if the Device has been Modified... this will Not necessarily work.

Next try:

- iOS: Not responding or does not turn on

- Also try DFU mode after try recovery mode

How to put iPod touch / iPhone into DFU mode « Karthik's scribblings

- If not successful and you can't fully turn the iOS device fully off, let the battery fully drain. After charging for an least an hour try the above again.

- If still not successful that usually indicates a hardware problem and an appointment at the Genius Bar of an Apple store is in order.