I love this song - so sad and beautiful, it makes me want to cry if i listen to it when 
sad. Anyhoo, heres the bass part

Verse - Played very quietly
G|--------------------------------|
D|7-7-7-7---------4-4-4-4---------|
A|--------5-5-5-5---------5-5-5-5-|
E|--------------------------------|

Occasionly it changes to
G|--------7-7-7-7-----------------|
D|7-7-7-7---------4-4-4-4---------|
A|------------------------5-5-5-5-|
E|--------------------------------|

Chorus
G|----------------------------------------------------------------|
D|--------------------------------4-4-4-4-4-4-4-4-----------------|
A|----------------5-5-5-5-5-5-5-5-----------------5-5-5-5-5-5-5-5-|
E|5-5-5-5-5-5-5-5-------------------------------------------------|

Bridge
G|----------------------------------------------------------------|
D|----------------4-4-4-4-4-4-4-4-----------------7-7-7-7-7-7-7-7-|
A|7-7-7-7-7-7-7-7-----------------5-5-5-5-5-5-5-5-----------------|
E|----------------------------------------------------------------|