Ok, I'm writing a simple for loop with an accumulator for my class tonight and can't figure out what I'm doing wrong. I want the program to accept the first 10 even numbers from the keyboard and add them up and display an error message if someone enters an odd number, heres what I've got so far and the only real problem I'm having is getting the numbers to add up correctly. If some one could give me a quick response it would be great... Thanks so much.

```
// This program will accept and sum the first 10 even numbers as read from the keyboard.
#include <iostream>
using namespace std;
//constants
const int terminatingvalue= 10;const int two=2;const int zero=0;
int main ()
{
//Variables
int ctr=1;int num;int sum=0;
// procces
for (int ctr=1; ctr<=10; ctr++)
{
cout<<"Enter a number"<<endl;
cin>>num;
if (num%two==zero)
{
sum=sum+num;
ctr++;
}
else
cout<<"Please enter an even number"<<endl;
cout<<"Enter a number"<<endl;
cin>>num;
}
cout<<"Total is:"<<sum<<endl;
//output
return 0;
}
```