ie8、9 post 跨域

//显示浮层
postAjax:function(url,param,callback){
    var loadScore = layer_.load(1,{shade: [0.8,'#393D49']});
    var ciphertext = root.encrypt(JSON.stringify(param),$.cookie('token'));

    var isIE = !!window.ActiveXObject;
    var ieMode = document.documentMode;
    var isIE8 = isIE && ieMode == 8;
    if(isIE8){
        var xdr = new XDomainRequest();
        xdr.open("POST", root.IPLocation+url);
        xdr.onload = function(){
            //Handle Response with xdr.responseText
            layer_.close(loadScore);
            var data = JSON.parse(xdr.responseText);
            if(data.result == true){
                if(data.tokenExpired) {
                    root.getTokenApply(function(data){
                        $.cookie('token',data);
                        token=data;
                        root.getJsonData(url,param,callback);
                    });
                }else{
                    callback(data.t);
                }
            }else{
                if(data.msg!=''){
                    layer_.alert(data.msg);
                }
            }

        }

        xdr.send(ciphertext.toString());
    }else{
        $.ajax({
            type: 'post',
            url:root.IPLocation+url,
            data: {info:ciphertext==""?"":ciphertext.toString()},
            context: this,
            success:function(data) {
                layer_.close(loadScore);
                if(data.result == true){
                    if(data.tokenExpired) {
                        root.getTokenApply(function(data){
                            $.cookie('token',data);
                            token=data;
                            root.getJsonData(url,param,callback);

                        });

                    }else{
                    callback(data.t);
                    }
                }else{
                    if(data.msg!=''){
                        layer_.alert(data.msg);
                    }
                }
            },error:function(){
                layer_.close(loadScore);
                layer_.alert("网络异常请稍后!");
            }
        });
    }

},