Why won't my iPhone charge on the regular charger?

I have an iPhone 3GS and I just recently updated it. The charger was working fine and now all of a sudden it won't charge on the regular charger but it will charge when I hook it up to my iPod dock. The charger works fine because it will charge my iPod touch but when I plug it into my phone it won't charge my phone.

I don't know any problem like that. Maybe plug into the computer dock to charge or get a new one. Sorry that i couldn't help.