jQuery.ajax implements different responses based on different Content-Types

$.ajax({
‘url‘: ‘GetWatermarkInfo.ashx‘,
‘type‘:‘post‘,
‘data‘: { ‘bgstyle‘: bgstyle, ‘watermark‘: watermark },
success: function (data, status, xhr) {
//使用XMLHttpRequest对象的getResponseHeader方法来获取content-type信息
var ct = xhr.getResponseHeader("content-type") || "";
if (ct.indexOf(‘application/json‘) > -1) {
if (data.Status == ‘error‘) {
alert(data.Message);
}
else if (data.Status == ‘ok‘) {
$(‘#watermarkImg‘).attr(‘src‘, 
‘GenerateWatermark.ashx?bgstyle=‘ + bgstyle + ‘&watermark=‘ + watermark);
}
else {
alert(‘unknown error!‘);
}
}
else {
alert(‘unexpectecd content-type!‘);
}
},
error: function (message) {
alert(‘error: ‘ + message);
}
})