Constructor cannot be applied to given types - newb needing clarification

Question

I have been reading various articles about serialisation, I am a newb to Java, I have searched for my errors, but despite reading a lot, I fail to understand why my program won't compile and what I need to change. I've read that my problem is the arguments in my constructor, but nothing seems to fix it. I'm not looking for someone to do it for me, just a pointer in the right direction. I have these classes in seperate files and have tried with them in a package and out of a package.

import java.io.Serializable;

public class Employee implements Serializable
{
   public String firstName;
   public String lastName;
   private static final long serialVersionUID = 5462223600l;
}

Employee.java has it's own file and it compiles on it's own

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class SerializaitonClass {        // held in SerializaitonClass.java

    public static void main(String[] args) {
        Employee emp = new Employee();
        emp.firstName = "Vivekanand";
        emp.lastName = "Gautam";

        try {
            FileOutputStream fileOut = new     FileOutputStream("./employee.txt");
            ObjectOutputStream out = new ObjectOutputStream(fileOut);
            out.writeObject(emp);
            out.close();
            fileOut.close();
            System.out.printf("Serialized data is saved in ./employee.txt file");
        } catch (IOException i) {
            i.printStackTrace();
        }
    }
}

Serialisation.java does not compile, specific errors are: Constructor Employee in Class Employee cannot be applied to given types. The compiler also doesn't recognise emp.firstName and emp.lastName

Finally, can anyone suggest a very simple guide to serialization, I think I am close to understanding everything, but I need something which is written in "Newb" terms.