function clear_keywords(id)
{
    var searchobj = document.getElementById(id);
    if(searchobj.value=="输入您要搜索的词"){
        searchobj.value="";
        searchobj.className="kuang2";
    }

}

function show_keywords(id)
{
    var searchobj = document.getElementById(id);
    if(searchobj.value==''){
        searchobj.value="输入您要搜索的词";
        searchobj.className="kuang";
    }
}

function searchvalue(obj)
{
    var searchvalue = obj.innerHTML;
    var keywordobj = document.getElementById("sykeywords");
    keywordobj.value = searchvalue;
}