Problem with combo system

Hi there! I'm having problems with my game, the game is a runner, but I need to make when the player colliding with an enemy stops time and have a certain time to execute a combo system time.

What I have is an array with randomly generated numbers. Each number means a special key (up, down, left, right). The combo appears on the screen, but what I need is to read the key pressed by the player and see if he did well.

Something like "one finger death punch" combos.

Thanks for your help!

Combo appears on screen, set a variable Combo = 1

When Combo = 1, do the following

set variable combo_timer = 0

set array_current_index to 0

1) Increase a combo_timer (timeout is 1 second or however fast you want the player to be able to react)

2) If player presses key, check that key with the combo_array(array_current index) to see if it matches..

3) If it matches, reset combo_timer and increase the array_current_index and repeat back to 1)

4) If it doesn't match or the combo_timer expires, then set a fail (kill the player? or whatever you have planned for a fail).. remember to set Combo=0

5) If array_current_index > number_of_combo_moves, then player has succeeded.. set Combo = 0

Hope that makes sense.