如何使用ajax从CodeIgniter中的动态生成表单上传图像

I want to upload an image to a local folder using jquery ajax. The complex part is i have the forms which are generated dynamically, and to those forms and fields i am giving the id to it so as to show which form is submitted as shown below. I am using following code but the image is not uploaded.I want to upload an image to a local folder usi