#define k_space 57
//define k_space = 57;
var k_nSt[50];
var in_n1 = 0;
var in_n2 = 0;

function kf2(var _nScanCode) {
	in_n1 = key_pressed(_nScanCode);
	in_n2 = in_n1 && !k_nSt[_nScanCode];
	k_nSt[_nScanCode] = in_n1;
	return(in_n2);
}
// usage:
if (kf2(k_space)) {

}