Please Help on H4 extension

[slp807]

Hi all
please calrify me

my husband changed form comapny A to company B and
he has his valid visa till october 20 2006 from company A and is gng for visa extension to canada from comapny B
i'm on H4 visa valid till october 20 2006 and am accompanying my husband for H4 visa extension to canada

My question is

will i need to file H4 extension seperately r the documents required for H1 for my husband are sufficient for H4 stamping also

Thanks
sreelatha