JS实现遮罩层

/* * 显示loading遮罩层 */function loading() { ???var mask_bg = document.createElement("div"); ???mask_bg.id = "mask_bg"; ???mask_bg.style.position = "absolute"; ???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 = 0.6; ???mask_bg.style.zIndex = 10001; ???document.body.appendChild(mask_bg); ???var mask_msg = document.createElement("div"); ???mask_msg.style.position = "absolute"; ???mask_msg.style.top = "35%"; ???mask_msg.style.left = "42%"; ???mask_msg.style.backgroundColor = "white"; ???mask_msg.style.border = "#336699 1px solid"; ???mask_msg.style.textAlign = "center"; ???mask_msg.style.fontSize = "1.1em"; ???mask_msg.style.fontWeight = "bold"; ???mask_msg.style.padding = "0.5em 3em 0.5em 3em"; ???mask_msg.style.zIndex = 10002; ???mask_msg.innerText = "正在执行,请稍后..."; ???mask_bg.appendChild(mask_msg);}/* * 关闭遮罩层 */function loaded() { ???var mask_bg = document.getElementById("mask_bg"); ???if (mask_bg != null) ???????mask_bg.parentNode.removeChild(mask_bg);}