use single session in multiple domain

Hi Floks

I am new in Boonex 7.0.7.  I have 2 website of boonex using same database for both application. i just want to know How did i use single session like gmail, google pluse and orkut.

please reply as soon as possible.

Thanks

Praveen Srivastav.

yaar... pata lage to mujhe bhi batana...