You are directly calling it.
document.getElementById("main_btn").addEventListener("click", hideId("main");
You should do that in a callback.
document.getElementById("main_btn").addEventListener("click", function (){
hideId("main");
});
You are directly calling it.
document.getElementById("main_btn").addEventListener("click", hideId("main");
You should do that in a callback.
document.getElementById("main_btn").addEventListener("click", function (){
hideId("main");
});