This is quiet simple...
G|----------------------------------------------------------------------------|
D|------3--3--4-----3--4------------------------------------------------------|
A|----3--3--------3-----------------------------------------------------------|
E|----------------------------------------------------------------------------|
Again and again...
If you want to change:
G|------------------------------------------------------------------------------|
D|------------------------------------------------------------------------------|
A|------8--8--9----8--9---------------------------------------------------------|
E|----8--8-------8--------------------------------------------------------------|
Good Luck!!