Grid posted records as editable if not posted, else non - editable :

  public int active()
{
    int ret;
    if(IPMPFComodityLines.Post == NoYes::Yes)
    {
        TransactionLinesGrid.allowEdit(false);
    }
    else
        {
            TransactionLinesGrid.allowEdit(true);
    }
    ret = super();
    return ret;
}