If, then, else

Hi patchers

Im new in max and i need help, i worked before in Visual basic, and i need help with the conditions or the If's

For a example:
in basic i do a condition this way:

if var1, var2, var3=1 then
var4=1
else
var4=0
endif

the 1 and the 0 in this case is for a LED in max.
If the leds 1,2 and 3 are activated then
led4 will be activated
else
led4 is disable
endif

please, i tried a lot on max, but cant find the way to do this simple if.

i need help...