I_Have_No_Name: First up, have a read of this thread.
Now, in answer to your question, when you cin into an int, the newline character is left in the input buffer, so when you do a cin.get at the end, the newline is taken and the program terminates. Here is some revised code that will suit your particular problem (there are many ways, all have which have been discussed on these boards):
Code:
#include <iostream.h>
int main(void)
{
int age;
cout << "Please input your age: ";
cin >> age;
while (cin.get() != '\n');
if (age < 100)
{
cout << "You are pretty young!";
}
else if (age == 100)
{
cout << "You are old";
}
else
{
cout << "Are you really that old?";
}
cin.get();
return(0);
}