javascript: var u = (document.URL).replace(/^http(s)?:\/\//g, "");
var p = u.lastIndexOf("/");
var u = u.substr(0, p);
var a = prompt("検索文字列を入力してください", "");
if (a != "" && a != null) {
    a = encodeURIComponent(a);
    a = a.replace("\u0025\u0032\u0030", "+");
    a = "https://www.google.co.jp/search?q=" + a + "+site:" + u;
    window.open(a);
}
void(0);