JS 添加mask

javascript: function loading() { var mask_bg = document.createElement("div");
    mask_bg.id = "mask_bg";
    mask_bg.style.position = "fixed";
    mask_bg.style.top = "0px";
    mask_bg.style.left = "0px";
    mask_bg.style.width = "100%";
    mask_bg.style.height = "100%";
    mask_bg.style.backgroundColor = "#777";
    mask_bg.style.opacity = 0.8;
    mask_bg.style.zIndex = 10001; if (document.getElementById("mask_bg") == null) { document.body.appendChild(mask_bg); } } loading();

function loaded() { var mask_bg = document.getElementById("mask_bg"); if (mask_bg != null) mask_bg.parentNode.removeChild(mask_bg); } document.getElementById("mask_bg").addEventListener("click", loaded);