[flexcoders] how to pass varible between screens?

[markflex2007]

Hi,

I have some screens under ViewStack like this
  
              <mx:ViewStack>             
                 <view:Form1View />
                 <view:Form2View />     
                 <view:Form3View />     
                 <view:ThankyouView />           
        </mx:ViewStack>

I have a variable in Form1View  but how I can get the variable in 
Form2View.

backend language have session variables,I am not sure if Flex also 
have the same function like session variable.

Please help me out.Thanks

Thanks

Mark