rowscopy 使用造成的错误

格式：
integer dwcontrol.RowsCopy ( long startrow, long endrow, DWBuffer copybuffer, datawindow targetdw, long beforerow, DWBuffer targetbuffer)

描述：
dwcontrol    The name of the DataWindow control, DataStore, or child DataWindow from which you want to copy rows.
startrow    The number of the first row you want to copy.
endrow    The number of the last row you want to copy.
copybuffer    A value of the dwBuffer enumerated data type (PowerBuilder) or an integer (Web ActiveX) identifying the DataWindow buffer from which you want to copy rows.For a list of valid values, see DWBuffer.
targetdw    A reference to the DataWindow control or DataStore object to which you want to copy the rows. Targetdw can be the same DataWindow (or DataStore) or another DataWindow (or DataStore).
beforerow    The number of the row before which you want to insert the copied rows. To insert after the last row, use any value that is greater than the number of existing rows.
targetbuffer    A value of the dwBuffer enumerated data type (PowerBuilder) or an integer (Web ActiveX) identifying the target DataWindow buffer for the copied rows. For a list of valid values, see DWBuffer.
关键说明：该函数复制一行或多行插入到每一行的前面。若要插入到最后一行，所指定的起始行号必须大于最后一行的号。