Aha, that is not what's in the code you posted above, hence our query as to what you've tried, rather than have us guess.
I hoped the example to be fairly self-explanatory, since there's not really anything special going on. At all. It's 'just' a function call in Javascript, something for which I recommend you to check out this. It's pretty much the same as you would do on the device.
int manual(String cmd){
String argumentVariable = cmd;
}
manual('pizza');
Is the exact same thing. manual is your function, and cmd is your function argument. That argument is then being used inside the function as a variable. argumentVariable would in this case be 'pizza', since that's what you passed it.
The exact same thing happens with the javascript. You make a function that expects two arguments. In the HTML you call that function and give it those two arguments. Those arguments are then used as variables to call the Particle.function(), which in turn expect's an argument itself.
The changes you made to the Javascript were unnecessary, and will not work, since the library only expects a certain amount of arguments. Not by accident, it expects
spark.callFunction(device_id, function_name, function_argument, callback_function);
Which is the reason why I named those variables that, so it'd be self-explanatory. Simply put, don't touch that entire function, unless you know what you're doing. The only thing that needs to be changed is the HTML part in the button. Quite literally, replace the words with their contents. For functionName insert the function name, and for the functionArgument insert the function argument. if your argument is I, Like, To, Insert, Commas, then that, as a whole, is your function argument. Don't go around creating new things inside the function, since that won't work.
If you've tried the page I've linked to, and you found a working argument, then that's what you need to insert there, nothing more, nothing less.
Answer me this, what is the exact function argument needed to toggle the 3rd relay on? Don't guess, try it with the page above, and report back if you've figured out what it's supposed to be. That saves us from guessing as well.
Though I might know the answer already (I think), I'm purposely keeping this a bit 'vague'. If you indeed intend on making this into kits of sorts, or making a guide for others to use, I want you to understand what's going on. There's absolutely no use in handing you the code, with you then not knowing what to say if people have questions regarding the kits you've provided them with. To make this work as intended, you need to how and why it works. The only way to learn that is to try, and read. For Javascript, W3schools has always been a good resource for information.