Determining program memory footprint in Task Manager

[ugh]

Hi all,

Does anyone know if I should take into account the value in the VM Size column of the Task Manager when determining the size of a proggie? I'm looking at Mozilla rite now and it's rather shocking:

Mem Usage: 55560K
VM Size: 58896K

Is the total mem used Mem Usage + VM Size or just Mem Usage?

TIA