在ajax里面嵌套ajax,要使用(async:false)

$.ajax({			        	
url:'',
async : false,
type:'post',
dataType:'json',
data:{'a':a,'b':b,'c':c},
success:function(data){                                                                  
    $.ajax({
        async : false,  
        url:'',
        type:'post',
        dataType:'json',
        data:{'waybillnumber':localStorage.result},
        success:function(re){
            window.location.href = "abc.php";
        },                                                    
    });                                                                                                                                                                                                                                                                                 
});