function checkShow(theshow, idx, r) {
   for(var i=0;i<idx;i++ ) {
      if( r == theshow[i] ) return 0;
   }
   
   return 1;
}

function choiceShowNum(theshow, idx, totalnum) {
  
   while(1) {
     var randvalue = Math.floor(totalnum*Math.random());
     if( randvalue == totalnum )
        randvalue--;
     if( checkShow(theshow, idx, randvalue) ) {
        break;  
     }
   }
   
   return randvalue;   
}

var thetitle = new Array();
var thedesc = new Array();
var theurl = new Array();
var theshow = new Array();
var showcount = 2;
var totalnum = 4;

theurl[0]="http://adcenter.conn.tw/redirect.php?ad_id=667&member=af000026556";
thetitle[0]="有腳臭得困擾嗎？脫鞋不再有異味";
thedesc[0]="專利除臭襪，三天徹底終結腳臭，作客、拜訪、脫鞋再也不尷尬";
theurl[1]="http://adcenter.conn.tw/redirect.php?ad_id=1480&member=af000026556";
thetitle[1]="噁心小強到處跑怎麼辦？";
thedesc[1]="網路評價最高的小強(蟑螂)終結產品，藥效長達3-6個月，徹底連鎖殺蟑，家中再也沒有小強";
theurl[2]="http://adcenter.conn.tw/redirect.php?ad_id=1370&member=af000026556";
thetitle[2]="去除惱人異味的絕佳法寶";
thedesc[2]="維妮舒獨家 NV5神奇抑菌術-為你打擊異味搔癢";
theurl[3]="http://adcenter.conn.tw/redirect.php?ad_id=2450&member=af000026556";
thetitle[3]="穿鞋不穿襪，乾爽不尷尬";
thedesc[3]="喜歡穿鞋不穿襪，穿造型鞋，使用鞋蜜粉，彩妝級蜜粉技術，讓你的雙腳乾爽無異味，拖鞋不尷尬";

   
var i;
for(i=0;i<showcount;i++ ) {
   theshow[i] = choiceShowNum(theshow, i, totalnum);
}

for(i=0;i<showcount;i++ ) {
   k = theshow[i];
   document.write('<div class="msgitem">\n');
   document.write('<div class="qa_title"><a href="' + theurl[k] + '" target="_blank">' + thetitle[k] + '</a></div>\n');
   document.write('<div class="qa_msg">' + thedesc[k] + '\n');
   document.write('</div></div>');
}