javascript - CSS, Java script not working properly after ajax call in php

I have called an ajax function in php page which works correctly and gives output as per requirement, but after ajax call, it does not return default css and javascript property to the Input type select,

Following is the code i have used for ajax call

it is returning ajaxpage.php in output, now i have one dropdown in the ajaxpage.php page , which is using choosen.css, choosen.js and multiselect.css as well as multiselect.js, but this dropdown is not working correctly and none of above css and js are working correctly because of above ajax page call, i have applied all the css and js in main page, please help me to solve this problem.