network connection with 2 virtual switches ?

Folks,

I have crated a small scenario and I am trying to figure out the soultion.

I have 4 VM.

VM1 & VM2   are on vswitch 1

VM2 & VM3 are on vswitch 2

There are no network physical network card in the ESX box.

Q1.  How will VM1 communicate with VM, I need some sort of connection of between vswitch1 and vswitch2 ...hwo should I do this ?

Q2. How do VMs communicate when they are are associated in the same Vswitch ?

Thanks