Please help me. I wrote a program from one of the tuturiols here. And when i run it. It only says:"Please input your age" and when i try to input my age it disappears. heres the source.

#include <iostream.h>
int main()
{
int age;
cout<<"Please input your Age";
cin>>age;
if (age<100)
{
cout<<"Your pretty young";
}
else if(age==100)
{
cout<<"You are old";
}
else
{
cout<<"You are really old";

}
return 0;
}
Thanks for your time.