if (nsnull != mContent) { PRInt32 length; mContent->ChildCount(length); *aLength = (PRUint32)length; } else {
if (mContent) { *aLength = mContent->GetChildCount(); } else {
nsChildContentList::GetLength(PRUint32* aLength){  if (nsnull != mContent) {    PRInt32 length;    mContent->ChildCount(length);    *aLength = (PRUint32)length;  }  else {    *aLength = 0;  }  return NS_OK;}