I just realised that if I do my project this way there will be no interactivity element at all and the initial idea was to use the keyboard to control the slide show.
I remember the class when we used the keyboard to point what image we want to see, so have to go back to tutorials and try to sort it out.
Tutorial 7: 'Using the keys on your keyboard to play an image / mapping an image to a key'

First I'm going to try with an image. To do this I need to hard code the image I want pd to open. My images have to be stored with pd file in one folder. I need to connect each render chain to specific key on the keyboard. I'll use the 'key object' which will show me the number every time I press the key on my keyboard. I need a 'number' and 'select object' also. The number box is connected to the 'key object' so every time I press an 'a' the 'key object' output 97 to a number box. I need to give a number inside 'select object' and when it will receives this specific number it will send a 'bang' and turn my image on. For the second render chain I need to put 98 ('b' key) in it's 'select object' and connect it to the number box. To avoid pressing my keys twice (each time I want it to start and stop an image to play) I need a 'message' with number '0' to be connected to 'select object' of the first render chain and to the 'toggle' of the second render chain. I need to add a second message with '0' and connect it to the 'select object' of the second render chain and the 'toggle' of the first render chain. In this way when I press an 'a' it will turn my first image and turn off the second and opposite.  

Next I'm going to try with four images. I picked 'a'(97), 'b'(98), 'c'(99), 'd'(100) keys to play my images. Using the same method I had to connect each '0' message to one 'select object' with the number, through the message's inlet and link it through the outlet to all 3 'toggles' of other images.

Now I try with my movies. I wanted to hard code my movie file name but it didn't work.