Just so you know, you can use this for debugging. It helped me a lot, and still does
error:function(x,e) {
if (x.status==0) {
alert('You are offline!!\n Please Check Your Network.');
} else if(x.status==404) {
alert('Requested URL not found.');
} else if(x.status==500) {
alert('Internel Server Error.');
} else if(e=='parsererror') {
alert('Error.\nParsing JSON Request failed.');
} else if(e=='timeout'){
alert('Request Time out.');
} else {
alert('Unknow Error.\n'+x.responseText);
}
}