关于异常的小程序出现debug assertion failed！错误的原因是什么？

#include<iostream.h>
#include<string.h>
class MyException
{
public:
 char *cause;
 MyException(char *in)
 {
  cause=new char[21];
  strcpy(cause,in);
 }
 void printmessage()
 {
  cout<<"Error!"<<cause<<endl;
  delete[] cause;
 }
 ~MyException()
 {
  delete[] cause;
 }
};
class person
{   int age;
public:
 void get()
 {
  cout<<"Enter age:"<<endl;
  cin>>age;
  MyException e("Problem with age!");
  if(age>100||age<0)
   throw e;
  else
   cout<<"Correct age. : )";
 }
};
void main()
{
 person pe;
 try
 {
  pe.get();
 }
 catch(MyException &x)
 {
  x.printmessage();
 }
} 

 

vc6.0编译通过，运行：当输入0-100之间的数时运行正常，当输入〉100的数时程序报错：

  debug assertion failed！

program：c:/documents and settings/administor/debug/excep_test.exe

file:dbgdel.cpp

line:47

expression: _BLOCK_TYPE_IS_VAILD(pHead->nBlockUse)

不知为何出现这个错误？？？