How to know the mode the browser running with ?

How to know the mode the browser running with ? i.e. Standards Mode, Quirks Mode ...   In Firefox and Opera you can determine if your browser is in "quirks mode" by checking page info. Using document.compatMode, will tell you the mode you are in with most browsers. In Chrome, Safari, and IE, run this javascript in the address …

How to detect client browser?

/****** Browser Detection ******/ function testCSS(prop) { return prop in document.documentElement.style; } var isOpera = !!(window.opera && window.opera.version); // Opera 8.0+ var isFirefox = testCSS('MozBoxSizing'); // FF 0.8+ var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0; // At least Safari 3+: "[object HTMLElementConstructor]" var isChrome = !isSafari && testCSS('WebkitTransform'); // Chrome 1+ var isIE = /*@cc_on!@*/false || …