Abnormal procedures, debugging:
(1) Press F12 to see the console;
(2) the page by F12 - Debugger - break point - click on the button to perform - to see if the data is incorrect;
(3) by F12-- network - clear all network requests - Click on the button - to view the request "Parameters" is correct - see the return value information (response);
(4) If the above did not solve the problem, to see whether the program was wrong things, such as: punctuation, letters, format ...