here's some of my old code...

would use a little code to define and reset the array
Code:
//setup possible object number pairs
	int_objects = 10; //global int
	for(i = 0; i < int_objects; i+=2){
		arr_objects[i] = i*10; //*10 for (0, 10, 20 etc...)
	}


then use this to pick the number
Code:
function get_object_number(){
	
	random_seed(0);
	
	//find number
	int int_temp_chose, int_temp_pos;
	
	int_temp_pos = integer(random(int_objects));
	int_temp_chose = arr_objects[int_temp_pos];
	
	int i;
	for(i = int_temp_pos; i < int_objects; i++){
		arr_objects[i] = arr_objects[i+1];
	}
	
	int_objects--;
	return(int_temp_chose);
}