function RandomImg(){ 
   Img=new Array(); 
   Img[0] =' <a href ="http://www.ntt-west-hokuriku.co.jp/" target="_blank"><img src="/imgs/ntt_neo_bnr.gif" height="45" width="350" border="0"></a> '; 
   Img[1] =' <a href ="http://www.actontv.com" target="_blank"><img src="/imgs/act-on.gif" height="45" width="350" border="0"></a> '; 
   Img[2] =' <a href ="http://meblog.jp" target="_blank"><img src="/imgs/meblog.gif" height="45" width="350" border="0"></a> ';

   var imgNum=Img.length; 
   var i=Math.floor(Math.random()*imgNum); 
   document.write(Img[i]); 
   } 

   RandomImg();