How about:
if(Field1 != 1 || Field2 != 1 || Field3 > Field4)
"Quit"
else
"Proceed"
That way as soon as you find out one of the conditions fails you can quit, and you won't need multiple (separate)
if
statements.
I'd advise against using something like
If Field 1 + Field 2 + Field 5 = 3 Then
, even if your quite sure of what the fields will be if something changes in the future you might end up with some unexpected behaviour, like if Field1 = 2, Field2 = 0 and Field5 = 1 it would still go through.