Subscript out of range error VBA

For i = 1 To wss.Cells(Rows.Count, "B").End(xlUp).Row
    poc(i) = wss.Cells(srow + 3, scolumn).Value     
    wsd.Cells(drow, dcolumn).Value = poc(i)
    drow = drow + 1
Next

This is the error I get

subscript out of range error