function SiteSearch(send_url, divTgs) {
	var str = $.trim($(divTgs).val());
	if (str.length > 0 && str != "输入关健字") {
	    window.location.href = send_url + "?q=" + encodeURI($(divTgs).val());
	}
	return false;
}

                <div class="input-box">
                    <input id="q" name="q" type="text" onkeydown="if(event.keyCode==13){SiteSearch('/plus/search.php', '#q');return false};" placeholder="输入关健字" x-webkit-speech="" />
                </div>
                <a href="javascript:;" onclick="SiteSearch('/plus/search.php', '#q');">
                    <i class="iconfont icon-search"></i>
                </a>