When I was entering a long  flight plan into my FMC, I entered a waypoint wrongly, I would like to remove it , but I found that the del key can't remove it, so how can I remove the mis-entered way-point so htat I can made my flight plan correct.

Thanks

If you select the select key to the left of the next waypoint (below the waypoint you want to delete in the LEGS page) it will place that waypoint in the Scratchpad line (lower part of the screen). That means you got the waypoint selected. Then click the line select key next to the waypoint you want to delete and it will over right it with the waypoint you selected earlier.

Hope this helps.