How to access the values into list

public student()
{
public List<student_details>studentdetails=new List<student_details>();
public student()//constructor
{
Student_details s=new Student_details();
{
s.Student_Name=//here i have access the value from Student_details class
}
}
}
public Student_details()
{
public string Student_Name{get;set;}
//I am getting a value of student name from  xml using another c# file
}