release keyboard input

[chainswap]

ok so here is a code i typed up to get simple input from the keyboard.

#include <conio.h>
#include <iostream>
using namespace std;

int main()
{
    int a = 0;       // just so the while loop will continue to go on
    while (a == 0){
     char key = ' ';
     key = getch();
     if (key != 27){ // backspace
     cout << "You entered: " << key << endl;}
     else 
          return(0);
}
cin.get();
}

ok so how would i get it to work but on key release and not press and i hope
this isnt too much of a noobish question >.>?

any help very much appreciated :D