I stored the button element and also the element to be changed into seperate variables. I added an onclick property to the button. When i click, it brings my function but on second click, it doesnt bring my function.

var button = document.getElementById("btn");

var divv = document.getElementById("div");

button.onclick = function(){

        if (divv.className = "."){

            //expand divv

            divv.className ="open";

            button.innerHTML = "Read less";

        } else{

            //shrink divv

            divv.className = ".";

            button.innerHTML = "Read more";
        };
} ```