$(document).bind('click', function(e) {

var e = e || window.event; //浏览器兼容性

var elem = e.target || e.srcElement;

while (elem) { //循环判断至跟节点，防止点击的是div子元素

if (elem.id && elem.id == 'search') {

return;

}

elem = elem.parentNode;

}

$('.search-tip').addClass("hide"); //点击的不是div或其子元素

});