function change() {
var w = window.innerWidth;
var h = window.innerHeight;
if(w > 480){
document.getElementById("btx6").style.cssText = "width:26%;";
document.getElementById("btx5").style.cssText = "width:26%;";
document.getElementById("btx4").style.cssText = "width:26%;";
document.getElementById("btx3").style.cssText = "width:26%;";
}
}
change();