This is my first tab and im only 11. So I hope that you like it. It is played 
entirely on the 4th and 2nd frets.

When the Saints Go Marching In (Intro)

E--------0--2------0--2------0--2------------
B---0--4------0--4------0--4------4----4----2
G------------------------------------4-------
D--------------------------------------------
A--------------------------------------------
E--------------------------------------------


There is the tab for the first few words, but here is the chorus.

            G        
Oh,when the Saints go marching in
D7         G              C
Yes we'll all get up and join them,
            G       C   D7    G
When the Saints go marching in.
 
There is the whole tab with chords. I hope you enjoy it. Reply if you liked it, 
and like I said I'm only 11.
Good Luck.