Crashing program

So I'm working on a little bit of code but somehow it keeps crashing if you hit a key on your keyboard.
What i want my program to do is:
if you press OK then it will continue
So i got that part to work easily(not even a challenge)
But now i don't want it to crash if you press a key.

Here is the code i use:

while status=="notDone" do
local event, bottun, x, y = os.pullEventRaw()
if x>23 and x<26 and y==13 then --Coordinates
status="complete"
installationp1()
else
end
end

The error i get:
startup:45: attempt to compare nil with a number

Please help me because I need my programs set up in such a way that they don't crash and that nobody can look into the code.

You need to check which event is coming in. That code assumes you're only going to get mouse_click events. You need to put that mouse_click event handling code in an if block that verifies that you have a mouse_click event.

Like Lydyd said you need to check if its a mouse click other wise its just going to check every event.

while true do
 local event, button, x, y = os.pullEventRaw()
 if event == "mouse_click" then
  if x>23 and x<26 and y==13 then
   -- code here
   break
  end
 end
end