Hello,
I, my wife and my 3 yr old son, are all having multiple entry Canadian visitor visa valid upto may 2013.

Now I have a job offer from 1st Aug 2011 to 31st july 2012 in Canada, for which I want to apply for work permit and my family will be accompanying me.

My query is do I need to fill visitor application forms for my spouse and child again or the visitor visa they are having already will suffice.
As they will allow my wife and son for a max of 6 months on visitor visa they are having right now, should I apply for them again so that they can stay for the whole duration of my employment.
If I need to apply for them then what are the forms which are to be filled for them (temporary visitor visa form or something else).
Please guide.
Regards Rahul.

If you hold a valid work permit and your dependents have entry visas valid past the term of such a work permit, it should be possible for the officials at the port of entry to admit them for the term of your work permit. If not, then you would have the option of processing an inland renewal to extend their stay in Canada if needed.