iBook G4

I can not access to itune store.Just coming up COULD NOT COMPLETE THE ITUNES STORE REQUEST.THE STORE MAY BE BUSY.CHECK YOUR INTERNET CONNECTION OR TRY AGAIN LATER.

About my mac.

MAC OS X

VERSION 10.4.11

PROCESSOR 1.33 GHZ POWER PC G4

MEMORY 512 MB DDG SDRAM.

Is any solution?Please help me.Thank you in regards.