ajax设置全局等待层
$(document).ajaxSend(function(event, jqxhr, settings) {
settings.indexL=layer.load(0, {shade: [0.1,'#fff']});
});
$(document).ajaxComplete(function(event,request, settings) {
layer.close(settings.indexL);
});每个新请求的settings 是不一样的!
