if statement + vlookup??

I need to fill in the third column on sheet 2 from the 3rd column in sheet 1. do I need an IF statement combined with vlookup??

sheet 1
mark l XYZ l 45
katy l ABC l 3
mark l ABC l 6
katy l XYZ l 45
mark l DEFl 4

sheet 2:
mark l XYZ l
katy l ABC l
mark l ABC l
katy l XYZ l
mark l DEF l

Can anyone help? I'm pretty bad with formulas. Thanks!!