Hi,
I got my h1 in 2007 but unfortunately I could not take it .Iam in h4 status.I was not in USA from sep 2007 & I came back before few months in h4 visa.My question here is whether there is any limited time for h1 transfer(amendment) from h4. I want to work after 1 or 2 months as I am taking care of my small baby right now but I want to go to work before H1 is invalid. Help me in this.Thanks in advance...

Normally employer must notify USCIS and cancel the visa in case the employee is unable to come to work in US.
Check with your employer first, and better discuss this issue with their attorney.

H1B usually is valid for a certain period.
If your employer cancelled it you will have to apply again.