var userAgent = window.navigator.userAgent.toLowerCase();
var wrt_cnt = '<a name="top">';

if(userAgent.indexOf("chrome") > -1) wrt_cnt += '<img src="/spc.gif" width="1" height="1" alt="">';

wrt_cnt +=
'</a>'
+ '<div id="pg_tp">'
+ '<a href="#top" title="ページトップ" accesskey="t">'
+ '<img src="/yell/imgs/pg_tp.jpg" width="113" height="50" alt="">'
+ '</a>'
+ '</div>';

document.write(wrt_cnt);