my iphone does not rotate the screen with rotation of phone

You likely have orientation lock on. this is covered in the icon explanation section of the manual:

iPhone User Guide (For iOS 4.2 and 4.3 Software)

This helped me ;-)

http://support.apple.com/kb/TS3805

You can also set the Side Switch to lock the screen orientation instead of silencing sound effects and notifications. In Settings, go to General > Use Side Switch to, then tap Lock Rotation.