function checkWebPSupport {
var webP = new Image;
webP.onload = function {
callback;
};
webP.onerror = function {
callback;
};
webP.src = 'data:image/webp;base64,UklGRjoAAABXRUJQVlA4IC4AAACyAgCdASoCAAIALmk0mk0iIiIiIgBoSygABc6WWgAA/veff/0PP8bA//LwYAAA';
}
checkWebPSupport {
if {
var images = document.querySelectorAll;
for {
images.src = images.getAttribute;
}
}
});