result = tableFrame->QueryInterface(NS_GET_IID(nsITableLayout), (void**)(&tableLayoutObject)); if (NS_FAILED(result)) return nsnull;
CallQueryInterface(tableFrame, &tableLayoutObject);
nsSelection::GetTableLayout(nsIContent *aTableContent){  // Get frame for table  nsIFrame  *tableFrame = nsnull;  nsresult result = GetTracker()->GetPrimaryFrameFor(aTableContent, &tableFrame);  if (!tableFrame) return nsnull;  nsITableLayout *tableLayoutObject = nsnull;  result = tableFrame->QueryInterface(NS_GET_IID(nsITableLayout), (void**)(&tableLayoutObject));   if (NS_FAILED(result)) return nsnull;  return tableLayoutObject;}