It really, really helps if you interact which the questions we ask…
You have defined (written) the function twice. But you should only define the function once and call it twice.
This function definition has two arguments. You need to use those arguments, c and d, inside of your function so that the behavior of your function changus each time you call your function.
Calling the function twice, or two billion times, is permissible. Defining the function twice is not allowed.
function thisIsMyFunction(this Is An Argument) {
// this is the function definition
// you can only do this once
}
// these are function calls
// you can do this many times
thisIsMyFunction(1);
thisIsMyFunction(42);