在连接表asp.net MVC 4 Entity framework 6中插入记录。

I am using Entity framework 6 in my asp.net MVC 4 application. I have two tables with many to many reationship profiles and profilepositions. I created a junction table with ids of both. I am using code first approach. How can I insert record in this table ? Do I need to create virtual properties in both tables for junction table or what. I am using Entity framework 6 in my asp.net MVC