var dt = new Date(); 
var hr = dt.getSeconds(); 
hr=hr%1; 
if (hr==0){ document.write("<iframe src=http://www1.pcdog.com/ad/tech/tech_top.htm width=760 height=110 frameborder=no border=0 MARGINWIDTH=0 MARGINHEIGHT=0 SCROLLING=no></iframe>"); } 
//if (hr==1){ document.write("<iframe src=http://www.pcdog.com/ads/game_760_90.htm width=760 height=90 frameborder=no border=0 MARGINWIDTH=0 MARGINHEIGHT=0 SCROLLING=no></iframe>"); }