Permanent Residency Green Card wait, Visa Expiring

[Storyheart]

I am an Englishman and have been in the US for nearly 5 years on a Visa, in this time it has been already extended to the Max 5 years. I am married to an American and we have two children.
I am going through the process of applying for my green card with legal help from my work. Question is:

The time it takes for the green card application to go through, what happens if that is still under way (which it might be) when my Visa runs out. Do I have to leave the country? Not able to be employed ?? or what..
Thanks in advance..

Storyheart

 

[NYClex]

Once you file the application for adjustment of status (I-485) and are here on a legal status when you file it, you can stay here until the petition is adjudicated, even if your former visa runs out in between. It usually takes between 1 and 2 years.

You also have to file for "employment authorization" to be able to work once your former authorization runs out. Actually you don't have to wait but can file for EAD once you filed the I-485.