How can I get LINQ to accept my argument?

I want to make "Create" option in ASP.NET MVC 3 in C#.
I am working with entity framework.

I want to make a method in one of my models that could insert all the data I posted into my action.

my model looks like this :

public class person { 
     public int id { get; set; }
     public string name{ get; set; }
     public string carBrand { get; set; }
     public string streetname{ get; set; }
 }
 

My view is strongly typed with this class above, making a "Create" page. So it creates the textboxes automatically for me.

The object Person, I gave my Controller has a parameter.

public ActionResult Index(person objectPerson)
 {
     //invoke method here
 }
 

Then I wanted my method, which came from the model, to take this object and add its properties to my database... but the problem is, it doesn't work the way I thought it would.

public void createPerson(person objectPerson)
 {
     db.MyTable.AddObject(objectPerson)
 }
 

giving the following error : the best overloaded method match has some invalid arguments

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