无法使用ExtJS将数据发布到ASP.Net Web API Controller

I am using ASP.Net MVC Web API for the first time. I have two functions written in my controller. First one gets the list of records and the second one is used to post data. My function to get the list of records work fine whereas the function to post data always fails. Here is the controller code: I am using ASP.Net MVC Web API for the first ti