Millisecond Forums

Hi!

I had already finished a script for running an experiment, but, after a meeting with my mentor, I was asked with making some alterations on the script. I am a complete newbie, so I really need healp.

But first, I will explain the experiment. 

It's an experiment in which participants are shown a series of 20 images of squares with 20 dots inside of each of them. The squares are divided by a vertical line and participants should answer in which side there are more dots. The images are shown for only one second, for they are not supposed to count the dots to give the answer. 

Subjects are rewarded in different ways according to the answer they give. For example, if they answer that the left side has more dots, they receive 5 cents. But if they answer the right side has more dots, they receive 10 cents. In the end of the experiment, they will receive the amount of money they have earned during the 20 trials.

The changes I am trying to implement are:

1) Subjects must answer by using the keyboard, pressing either the keys E or I (mouse was the input device before).
2) Subjects should answer while they see the images (before participants would answer on another screen, just after seeing the images).
3) Subjects must be able to click on something (the screen, a button etc) and stop the image on the screen to count the dots, if they want to. Otherwise, they will see the image for only 1000 milliseconds.
4) For half of the images, there are mot dots on the left side. For the other half, there are more dots on the right side. I need to randomize the images' presentation as well as to ble able to track whether participants have chosen the correct answer or not.

I have been trying to implement them, but I have been facing many errors which I do not know how to fix. 

I am attaching the script as well all the files below. 

Thanks in advance.