JavaScriptで検索キーワードを取得

サンプル

function getSearchQuery (referrer) {
    if (/[?&](kw|MT|name|p|q|qt|query|search|word)=([^&]+)/.test (referrer || document.referrer)) {
        var query = RegExp.$2;
        return eval ("Unescape" + GetEscapeCodeType (query) + "('" + query.replace (/\+/g, " ") + "')").replace (/^\s+|\s+$/g, "");
    }
    return null;
}