可复制弹窗框

function myalert(str) 

{ 

var shield = document.createElement("DIV"); 

shield.id = "shield"; 

shield.style.position = "absolute"; 

shield.style.left = "0px"; 

shield.style.top = "0px"; 

shield.style.width = "100%"; 

shield.style.height = document.body.scrollHeight+"px"; 

shield.style.background = "#fff"; 

shield.style.textAlign = "center"; 

shield.style.zIndex = "25"; 

var alertFram = document.createElement("DIV"); 

="alertFram"; 

alertFram.style.position = "absolute"; 

alertFram.style.left = "50%"; 

alertFram.style.top = "50%"; 

alertFram.style.marginLeft = "-225px"; 

alertFram.style.marginTop = "-75px"; 

alertFram.style.width = "450px"; 

alertFram.style.height = "150px"; 

alertFram.style.background = "#ff0000"; 

alertFram.style.textAlign = "center"; 

alertFram.style.lineHeight = "150px"; 

alertFram.style.zIndex = "300"; 

strHtml = "<ul style=\"list-style:none;margin:0px;padding:0px;width:100%\">\n"; 

strHtml += " <li style=\"background:#DD828D;text-align:left;padding-left:20px;font-size:14px;font-weight:bold;height:25px;line-height:25px;border:1px solid #F9CADE;\">[自定义提示]</li>\n"; 

strHtml += " <li style=\"background:#fff;text-align:center;font-size:12px;height:120px;line-height:120px;border-left:1px solid #F9CADE;border-right:1px solid #F9CADE;\">"+str+"</li>\n"; 

strHtml += " <li style=\"background:#FDEEF4;text-align:center;font-weight:bold;height:25px;line-height:25px; border:1px solid #F9CADE;\"><input type=\"button\" value=\"确 定\" onclick=\"doOk()\" /></li>\n"; 

strHtml += "</ul>\n"; 

alertFram.innerHTML = strHtml; 

document.body.appendChild(alertFram); 

document.body.appendChild(shield);  

this.doOk = function(){ 

alertFram.style.display = "none"; 

shield.style.display = "none"; 

} 

alertFram.focus(); 

}