ButtonX and ButtonY are the co-ordinates of the button. You also have to make something to click inside the box then send in the code (where 'SomethingToFillIn' is). Then replace 'SomethingToCheckYouClickedOkayRight?' with something to make sure the button is pressed (like if the page reloads with a red image saying 'incorrect' or 'correct', you could check for that). I think that it would be best for you to follow basic scar tutorials so you can get the hang of basic scar coding (which should be more than enough to do what you want). Also, you need to include srl to use the 'Mouse' procedure, but I'm guessing you don't have it installed, so you should probably just use 'MoveMouse' and 'ClickMouse'.
Lastly, I think it is morally wrong to 'cheat' a game using scar, as scar/srl was meant to automatically play the game in a more intelligently demanding way rather than the traditional way of 'playing by rules' (so to speak).
By reading this signature you agree that mixster is superior to you in each and every way except the bad ways but including the really bad ways.