My Iphone 4s won't start it just shows the apple logo

I tried holding the home button and sleep button together for few seconds this is not work.
please please please help me

Check out youtube,

that happened to me! Scary, huh.

Does iTunes recognize your phone when you plug in? If no, you can try to force it into iTunes.

Once in iTunes, you can easily restore your phone, and it will work again.

To force it into iTunes: (first of all make sure you have the latest version of iTunes!)

*Hold both home button and sleep button until the apple logo reappears (you'll see a slight switch in the screen)
*Then release the sleep button while still holding the home button.
* While still holding the home button, plug into your computer.
* The Itunes logo will appear on your Iphone screen.
* Release the home button.
* Click the restore button.

IMPORTANT: Your phone will be resetted to the original settings!

Afterwards you can put your back up back onto your Phone. (It depends on how often you connect your phone to iTunes, whether you can retrieve all your data, or just a tiny bit. Every time you plug in to iTunes, a back up is automatically made).