IF multiple criteria with VLOOKUP

I cant fix my formula. Or better i dont even know if im on right way. My geal is: row B is empty, there will be formula.

    A    B    C    D
1  ID   TYPE       ID_Criteria
2   1   FIRM       4
3   0   HUMAN
4   3   FIRM
5   4   CORPORATE

IF A2 > 0 then VLOOKUP in row D, if false B2 is FIRM. Otherwise IF A2 > 0 then VLOOKUP in row D and TRUE B2 is CORPORATE. And last condition when A2 < 0, row return Human.

My formula:

=IF(A2>0,IF((VLOOKUP(A2,D1:D4,1,0),"CORPORAT","FIRM"),"HUMAN"))

Any ideas ?