Jquery 切换不同图片示例代码

#sidebar div#live_chat a { 
background: url("scroll/live_chat1.jpg") ; 
height: 76px; 
} 
#sidebar div#live_chat a:hover { 
background: url("scroll/live_chat2.jpg") ; 
} 
#sidebar div#customer_survey a { 
background: url("scroll/survey1.jpg") ; 
height: 75px; 
} 
#sidebar div#customer_survey a:hover { 
background: url("scroll/survey2.jpg"); 
} 
#sidebar div#newsletter_sign a { 
background: url("scroll/newsletter_sign_bg.jpg") ; 
height: 76px; 
} 
#sidebar div#newsletter_sign a:hover { 
background: url("scroll/newsletter_sign_bg1.jpg") ; 
height: 76px; 
} 
#sidebar div#back_top a { 
background: url("scroll/back_top1.jpg"); 
height: 40px; 
} 
#sidebar div#back_top a:hover { 
background: url("scroll/back_top2.jpg") ; 
} 
#sidebar div a { 
cursor: pointer; 
display: block; 
width: 77px; 
}