Green Day - Warning
Standard Tuning

The chords are just A - D - G - D (open chords)

Main Riff: (might actually be the bass playing this)
|---------------------------------------------------------------------|
|----------3-3-----3-3-----3-3----------------------------------------|
|--2-2-----2-2-----0-0-----2-2-----2-2--------------------------------|
|--2-2-----0-0-2-4-0-0-4-2-0-0-----2-2--------------------------------|
|--0-0-2-4---------------------4-2-0-0--------------------------------|
|---------------------------------------------------------------------|

Riff II: (with tremolo effect, hit first chord and let the top notes
          ring while you play the bottom notes)
|---------------------------------------------------------------------|
|---------------------------------------------------------------------|
|--2------------------------------------------------------------------|
|--2------------------------------------------------------------------|
|--0--4-0--------0-0--4-0---------------------------------------------|
|---------3--0-------------3--0---------------------------------------|

tabbed by zipztabs.com
Enjoy!