// slightly modified from http://www.hunlock.com/blogs/Totally_Pwn_CSS_with_Javascript

function getCSSRule(ruleName, deleteFlag)
{
	ruleName=ruleName.toLowerCase();
	if (document.styleSheets) {
		for (var sheet=0; sheet<document.styleSheets.length; sheet++) {
			var styleSheet=document.styleSheets[sheet];
			var rule=0;
			var cssRule=false;
			do {
				if(styleSheet.cssRules) { cssRule = styleSheet.cssRules[rule]; }
				else if (styleSheet.rules) { cssRule = styleSheet.rules[rule]; }

				if (cssRule && cssRule.selectorText.toLowerCase()==ruleName)
				{
					if (deleteFlag=='delete')
					{
						if(styleSheet.removeRule()) { styleSheet.removeRule(rule); }
						else if(styleSheet.deleteRule()) { styleSheet.deleteRule(rule); }
						else { return false; }
						return true;
					}
					else { return cssRule; }
				}
				rule++;
			} while (cssRule)
		}
	}
	return false;
}


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


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