Click "Change style" in the navigation bar of jquery, and click "Change style" in the navigation bar of jquery.
<! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN "" http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd "> <Html xmlns =" http://www.w3.org/1999/xhtml "> <Head> <title> new document </title> <meta http-equiv =" Content-Type "content =" text/html; charset = UTF-8 "/> <body> <style> * {margin: 0; padding: 0; border: 0px; list-style: none; margin: 0 auto ;} * a {text-decoration: none; color: # FFF;} ul {width: 800px; height: 30px; background-color: # C33;} ul li {float: left; width: 160px; height: 30px; line-height: 30px; text-align: center; color: # FFFFFF;} ul li a {color: # FFFFFF; display: block; width: 160px; height: 30px; text-decoration: none ;}. first {background-color: # 0000FF;} ul li a: hover {color: # FFF; display: block; width: 160px; height: 30px; text-decoration: underline; background-color: # 03F ;} </style> <script type = "text/javascript" src = "jquery-1.7.1.min.js"> </script> <script language = "javascript" type = "text/javascript"> $ (document ). ready (function () {$ ("li "). each (function (index) {$ (this ). click (function () {$ ("li "). removeClass ("first"); $ ("li "). eq (index ). addClass ("first ");});});}); </script>