var light= (getCookie("light")=="" ? true : getCookie("light"));

document.getElementById("light").width=size/4;

function switchLight() {
    console.log("light avant "+light);
    light=(light=="true" ? "false" : "true");
    console.log("light après "+light);
    setCookie("light",light,30);
    applyLight(light);
}

function applyLight(li) {
    console.log("app li "+li);
    document.getElementById("light").src="ress/"+(li=="true" ? "light" : "dark")+".png";
    document.getElementById("logo").src="ress/logo_"+(li=="true" ? "clair" : "dark")+".png";
    document.getElementsByTagName("body")[0].classList.add((li=="true" ? "day" : "night"));
    document.getElementsByTagName("body")[0].classList.remove((li=="true" ? "night" : "day"));
}

applyLight(light);