Calling interface driven method from one project to another

Question

namespace Project1

{

public interface IInterface1

{

void Method();

}

public interface IInterface2 : IInterface1

{

void Method();

void Method2();

}

// Here we are implementing methods for get and sent data to database

public class GetSentData: IInterface1

(

void Method();

void Method2();

)

}

note: We are making a .dll of above mentions interfaces and class.

//This is a another solution

//I add reference of Project1 into project2

Namespace project2

{

public class Acess

{

//Here we want to call above class method by using the interface driven class

IInterface1 myinterface=new GetSentData();

myinterface.Method(); 

//Like This but am getting error as: Object is not set to an instance of object

}

}

//Please Suggest with your valuable answers