Filtering top 20 values error.

[zabiullakhan]

i want to filter top 20 values only.. the below code gives me error
"AutoFilter method of range class failed"

GrabAdd = Selection.Address
Selection.AutoFilter GrabAdd, Criteria1:="20", Operator:=xlTop10Items

Selection.Address has the header address of the col i want to pick top 20 in that col and values of the col is already sorted.

Please help