背景色などjsのアラートスタイルを変更する_javascriptスキル

window.alert = function(str)
{
varshield = document.createElement("DIV");
shield.id = "shield";
shield.style.position = "absolute"; ";
shield.style.top = "0px";
shield.style.width = "100%";
shield.style.height = document.body.scrollHeight "px";
//ポップアップ ダイアログボックスの背景色
shield.style.background = "#fff";
shield.style.textAlign = "center";
shield.style.zIndex = "25"; ;
/ /背景透明 IE 有効
//shield.style.filter = "alpha(opacity=0)";
var warningFram = document.createElement("DIV"); id="alertFram" ;
alertFram.style.position = "50%";
alertFram.style.top = "50%"; alertFram.style.marginLeft = "-225px";
alertFram.style.marginTop = "-75px";
alertFram.style.width = "450px"; ;
alertFram.style.background = "#ff0000";
alertFram.style.textAlign = "150px"; "300";
strHtml = "

n";
strHtml = "
• n";
  strHtml = "
• " str "
n";
strHtml = "
• n";
  strHtml = "

n";
document.body.appendChild(alertFram); 🎜>document.body.appendChild(shield);
var ad = setInterval("doAlpha()",5);
this.doOk = function(){
alertFram.style.display = "none ";
shield.style.display = "none";
}
alertFram.focus();
document.body.onselectstart = function(){return false;};
}


効果は写真の通りです