ajax跨域调用和非跨域调用的写法

//支持跨域调用$.ajax({  type:"POST",  async :false,  url:"http://web3.com:9080/authority/dept/hellob.shtml?userName=zqb&callback=?",  dataType:"jsonp",  success:function(data){  //alert(data);console.log(data);},  error:function(){  alert("error");  }    });      }  //不支持跨域调用  function b(){    $.ajax({        type: "post",        dataType: "html",        url: "http://web3.com:9080/authority/dept/hellob.shtml?userName=zqb",        data: "",        success: function (data) {        console.log(data);        }    });    }