if ((nsnull != aSelector->mClass) || (nsnull != aSelector->mTag)) {
if ((nsnull != aSelector->mClass) || (nsnull != aSelector->mID)) {
PRBool CSSStyleSheetImpl::SelectorMatches(nsCSSSelector* aSelector, nsIContent* aContent){  PRBool  result = PR_FALSE;  if ((nsnull == aSelector->mTag) || (aSelector->mTag == aContent->GetTag())) {    if ((nsnull != aSelector->mClass) || (nsnull != aSelector->mTag)) {      nsIHTMLContentPtr htmlContent;      if (NS_OK == aContent->QueryInterface(kIHTMLContentIID, htmlContent.Query())) {        if ((nsnull == aSelector->mClass) || (aSelector->mClass == htmlContent->GetClass())) {          if ((nsnull == aSelector->mID) || (aSelector->mID == htmlContent->GetID())) {            result = PR_TRUE;          }        }      }    }    else {      result = PR_TRUE;    }  }  return result;}