function getCSSRule(ruleName, deleteFlag) {
   ruleName=ruleName.toLowerCase();
   if (document.styleSheets) {
      for (var i=0; i<document.styleSheets.length; i++) {
         var styleSheet=document.styleSheets[i];
         var ii=0;
         var cssRule=false;
         do {
            if (styleSheet.cssRules) {
               cssRule = styleSheet.cssRules[ii];
            } else {
               cssRule = styleSheet.rules[ii];
            }
            if (cssRule)  {
               if (cssRule.selectorText.toLowerCase()==ruleName) {
                  if (deleteFlag=='delete') {
                     if (styleSheet.cssRules) {
                        styleSheet.deleteRule(ii);
                     } else {
                        styleSheet.removeRule(ii);
                     }
                     return true;
                  } else {
                     return cssRule;
                  }
               }
            }
            ii++;
         } while (cssRule)
      }
   }
   return false;
}

function killCSSRule(ruleName) {
   return getCSSRule(ruleName,'delete');
}

function addCSSRule(ruleName) {
   if (document.styleSheets) {
      if (!getCSSRule(ruleName)) {
         if (document.styleSheets[0].addRule) {
            document.styleSheets[0].addRule(ruleName, null,0);
         } else {
            document.styleSheets[0].insertRule(ruleName+' { }', 0);
         }
      }
   }
   return getCSSRule(ruleName);
}