VBA运行时错误1004错误

今天帮人做一个VBA宏，　很久没干这活了.


Workbooks(dirname).Sheets(i).UsedRange.Copy
Sheets(i).Range("A" & usedRows).Select

Selection.PasteSpecial Paste:=xlPasteValuesAndNumberFormats, Operation:= _
xlNone, SkipBlanks:=False, Transpose:=False

Selection.PasteSpecial Paste:=xlPasteFormats, Operation:=xlNone, _
SkipBlanks:=False, Transpose:=False

usedRows = usedRows + Workbooks(dirname).Sheets(i).UsedRange.Rows.Count



在执行到RANGE(1,1).SELECT时，一直提示运行时错误１００４，
原来是执行SELECT之前，需要将当前的WORKBOOKS, SHEETS激活.
WorkBooks(...).activate
Sheets(i).activate