work experience letters for H4

[googol]

Hi,
I\'d be getting married in Feb and my wife would need
an H4 visa (from delhi consulate). I already have a valid
H1 stamp for my current employer.

One of the docs asked for are my work experience letters.
I have been working at my present company for more than two
years. Do i need to get experience letter from my previous
employers? does anybody know? it does seem that they shouldnt
matter but i just want to be sure.

thanks a lot.