function getCSSRule(ruleName, deleteFlag, prop) {
	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 && cssRule.selectorText) {
					if (cssRule.selectorText.toLowerCase().split(/,\s*/)[0]==ruleName.split(/,\s*/)[0] && ((cssRule.style && cssRule.style[prop]) || !prop)) {
						if (deleteFlag=='delete') {
							if (styleSheet.cssRules) {
								styleSheet.deleteRule(ii);
							} else {
								styleSheet.removeRule(ii);
							}
							return true;
						} else {
							return cssRule;
						}
					}
				}
				ii++;
			} while (cssRule);
		}
	}
	return false;
}

function getAllCSSRules(prop, unit) {
	var rules=[];
	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 && cssRule.selectorText && cssRule.style[prop] && (cssRule.style[prop].indexOf(unit)>-1 || !unit)) {
					rules.push(cssRule);
				}
				ii++;
			} while (cssRule);
		}
	}
	return rules;
}

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);
}