我是新手,请问这个程序哪里出了问题,谢谢

我先建立了一个Student类
using System;
public class Student
{
private string name;
private string id;
private int credits;
public Student(string name,string id)
{
           this.name=name;
   this.id=id;
}
public string getName()
{
return name;
}
public void setName(string newName)
{
name=newName;
}
public string getId()
{
return id;
}
public void setId(string newId)
{
id=newId;
}
public int getCredits()
{
return credits;
}
public void setCredits(int newCredits)
{
credits=newCredits;
}
public void print()
{
Console.WriteLine("{0}  ({1})  ({2})",name,id,credits);
}
}然后
using System;
using System.Collections;
public class OopClass
{
        private string instructor;
private string room;
private string dayAndTime;
private int capacity;
private ArrayList studentList;
public OopClass(int maxNumberOfStudents)
{
instructor=null;
room=A412;
dayAndTime=Tuesday;
studentList=new ArrayList();
                            capacity=maxNumberOfStudents;
}
public void enrolStudents(Student newStudent)
{
if(studentList.Count==capacity)
Console.WriteLine("本班已满,不能再登记.");
else
studentList.Add(newStudent);
}
public int numberOfStudents()
{
return studentList.Count();
}
public void setRoom(string roomNumber)
{
room=roomNumber;
}
public void setTime(string dayAndTime)
{
this.dayAndTime=dayAndTime;
}
public void setStructor(string instructorName)
{
instructor=structorName;
}
public void printList()
{
Console.WriteLine("面向对象程序设计  {0}",dayAndTime);
Console.WriteLine("老师:{0}     教室:{1}",instructor,room);
Console.WriteLine("本班同学:");
}
public static void Main(string[] args)
{
OopClass oopClass=new OopClass(50);
Student kay=new Student("陈一心","S042450");
kay.setCredits(3);
kay.print();
Student jemmy=new Student("林二圣","S042451");
jemmy.setCredits(5);
jemmy.print();
Student jay=new Student("李三多","S042354");
jay.setCredits(9);
jay.print();
oopClass.enrolStudents (kay);
                           oopClass.enrolStudents (jemmy);
oopClass.enrolStudents (jay);
oopClass.instructor("林邦杰");
oopClass.setRoom("B603");
oopClass.setTime("Friday 9:00am");
oopClass.printList();
               }
}
我运行时出现了错误
程序“F:\任益枚\ch01\Student.cs\Student.cs\obj\Debug\Student.cs.exe”未定义入口点
F:\任益枚\ch01\OopClass.cs\Class1.cs(20): 找不到类型或命名空间名称“Student”(是否缺少 using 指令或程序集引用？)
我又在Student类里定义了入口,就只出现了
F:\任益枚\ch01\OopClass.cs\Class1.cs(20): 找不到类型或命名空间名称“Student”(是否缺少 using 指令或程序集引用？)
请问哪里出问题了?十分感谢