function banner(imgSource,url,chance,type) {
   this.imgSource = imgSource;
   this.url = url;
   this.chance = chance;
   this.type = type;
}
function dispBanner() {
	with (this)
	switch (type){
		case "img":
			document.write("<A HREF=" + url + " target=_blank><IMG SRC=" + imgSource + "  BORDER=0></A>");
			break;
		case "html":
			document.write("<IFRAME WIDTH=148 HEIGHT=400 MARGINWIDTH=0 MARGINHEIGHT=0 HSPACE=0 VSPACE=0 FRAMEBORDER=0 SCROLLING=no BORDERCOLOR=#FFFFFF SRC=http://smsimg.163.com/banner/"+ imgSource + "148x400.html></iframe>");
			break;
		case "flash":
			document.write("<embed src="+imgSource+" quality=high width=468 height=60 type=application/x-shockwave-flash pluginspage=http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash></embed>");
			break;
		default:
			document.write("");
	}
    
}


banner.prototype.dispBanner = dispBanner;
banners = new Array();


// flash , html , img 代表三种不同的广告模式
// 200 之类的数目是设置出现的机率
// banner列表 
banners[0] = new banner("http://www.chahua.org/adv/peixun_445x60_wh_12.gif","http://www.chahua.org/art/trade/training/index.html",200,"img"); 

//banners[0] = new banner("adv/sh_468x60_1212.swf","",100,"flash"); 
//banners[1] = new banner("adv/sh_468_60_0713.swf","",100,"flash"); 

//banners[1] = new banner("http://www.chahua.org/adv/ill_sh.swf","",100,"flash"); 
//banners[0] = new banner("http://bbs.chahua.org/adv/gold_adv.gif","http://www.chahua.org/drawn/new.php?hid=1",500,"img"); 
//banners[0] = new banner("http://bbs.chahua.org/adv/wuhan.gif","http://www.chahua.org/bbs/read.php?tid=46778&page=1&toread=1",500,"img"); 

//banners[0] = new banner("http://bbs.chahua.org/adv/illustrator_21.gif","http://bbs.chahua.org/read.php?tid=42085&fpage=1&toread=1",200,"img"); 

//banners[0] = new banner("06_mmspromo","",300,"html");  
//banners[0] = new banner("03_colorlife","",100,"flash");
//banners[1] = new banner("04_colorcar","",100,"flash");
//banners[2] = new banner("03_pinklady","",100,"html");
//banners[3] = new banner("06_mmspromo","",300,"html");  
//banners[4] = new banner("04_beautyfactory","",300,"flash");  
//banners[5] = new banner("03_mmvote","",100,"flash");  
//banners[6] = new banner("05_sale","http://mms.163.com/sale.jsp",100,"img");  
//banners[7] = new banner("05_spering_","http://mms.163.com/cm_lv2_sound.jsp?rtype=2",500,"img");  

sum_of_all_chances = 0;
for (i = 0; i < banners.length; i++) {
  sum_of_all_chances += banners[i].chance;
}
function randomBanner() {
  chance_limit = 0;
  randomly_selected_chance = Math.round((sum_of_all_chances - 1) * Math.random()) + 1;
  for (i = 0; i < banners.length; i++) {
    chance_limit += banners[i].chance;
    if (randomly_selected_chance <= chance_limit) {
      banners[i].dispBanner();
      break;
    }
  }
}
this_banner = randomBanner();