I'm pretty sure i did something like this in the code:
if(Input.GetAxis("Mouse ScrollWheel") > 0) block++;
if(Input.GetAxis("Mouse ScrollWheel") < 0) block--;
if(block < 0) block = maxBlock;
if(block > maxBlock) block = 0;
I looked for an input axis rather than a Input.GetKeyDown, so just replace this section with something like that.