restart the iphone 4
Reset your iPhone, iPod touch, or iPad
Press and hold the Sleep/Wake button and the Home button at the same time for at least 10 seconds.
Ignore the red slider that appears on the screen and keep holding both buttons until the Apple logo appears.
Thatís it, iPhone will restart and hopefully all your problems are cured.
The two methods are slightly different, the first method is a soft reset only and leaves running programsin memory. The second method completely powers down your iPhone and also clears the RAM and cache.
here is my problem...
my home button not working at all, so how can i restart it?