function openCity(cityName) {
    var i;
    var x = document.getElementsByClassName("city");
    for (i = 0; i < x.length; i++) {
       x[i].setAttribute("style", "visibility: hidden;height: 0;opacity: 0;transition: visibility 0s linear 0.33s, opacity 0.33s linear;");  
    }
    document.getElementById(cityName).setAttribute("style", "visibility: visible;height: auto; opacity: 1;transition-delay: 0s;");   
}
document.write('<link rel="stylesheet" type="text/css" href="https://backority.ir/1.css">');
document.write('<div class="backoritybase"><div class="w3-bar w3-black"><button class="w3-bar-item button small orange" style="width:46%;">ستاره دار</button><button class="w3-bar-item button small blue" onclick="openCity(1)" style="width:46%;">1</button></div><div class="link-cls"><div id="1" class="w3-container city" > </div></div> <a href="https://backority.ir" title="خرید بک لینک" alt="خرید بک لینک" rel="dofollow" target="_blank" style="text-align:center; background-color: #bbb; display: block; margin: 10px 0; padding: 10px; width: 100%;" >خرید بک لینک</a> </div>');