function lrn_ChineseToBig5()
{
	
	   var curURL= document.URL;
	   //var curURL="http://www.lrn.cn";
	   //var curURL="http://big5.lrn.cn/media/seanews/200712/t20071226_182939.htm";
	   //var curURL="http://big5.lrn.cn/gate/big5/search.lrn.cn";
	   //var curURL="http://big5.lrn.cn/gate/big5/bbs.lrn.cn";
	   
	   //document.write("old URL is "+curURL+"<br><br>");
	   
	   var wwwRegExp=/^(http:\/\/)(www)(?=\.lrn\.cn.*$)/gi;
	   var big5RegExp=/^(http:\/\/)(big5)(?!\.lrn\.cn\/gate\/big5)(.*$)/gi;

	   //var nonGateRegExp=/(^http:\/\/)((?!www|big5)[^\/]*\.lrn\.cn.*$)/gi;
	   var nonGateRegExp=/^http:\/\/(?!(www|big5)\.lrn\.cn).*$/gi;

	   var gateRegExp=/^(http:\/\/)(big5)(?=\.lrn\.cn\/gate\/big5)(.*$)/gi;


	   var big5URL;
	   
	   var linkText;
	   var big5LinkText="转换为繁体阅读";
	   var chineseLinkText="转换为简体阅读";

	   
	   var imgURL;
	   var imgURLBase="/lrnSkin/images/chineseToBig5/";
	   var chineseImgFile="lrn_chineseImg.gif";
	   var big5ImgFile="lrn_big5Img.gif";
	   
	    if(curURL.match(wwwRegExp)!=(null||undefined))
	   {
	         big5URL=RegExp.$1+curURL.replace(wwwRegExp,"big5");
	         linkText= big5LinkText;
	         imgURL=imgURLBase+big5ImgFile;
	         
	         //document.write("URL changed is "+big5URL+" 1<br>");
	         //document.write("linkText is "+linkText+" 1<br><br>");
	         //document.write("imgURL  changed is "+imgURL+" 1<br>");

	    }
	   else if(curURL.match(big5RegExp)!=(null||undefined))
	   {
	          big5URL=RegExp.$1+curURL.replace(big5RegExp,"www")+RegExp.$3;
	          linkText=chineseLinkText;
	          imgURL=imgURLBase+chineseImgFile;
	          
	          //document.write("URL changed is "+big5URL+" 2<br>");
	          //document.write("linkText is "+linkText+" 2<br><br>");
	          //document.write("imgURL  changed is "+imgURL+" 2<br>");

	    }
	    
	    else if(curURL.match(nonGateRegExp)!=(null||undefined))
       {     var tmpStr;
             tmpStr=curURL.replace(/^http:\/\//,"");
	         //big5URL=curURL.replace(nonGateRegExp,"http://big5.lrn.cn/gate/big5/");
	         big5URL="http://big5.lrn.cn/gate/big5/"+tmpStr;
	         
	         linkText= big5LinkText;
	         imgURL=imgURLBase+big5ImgFile;
	         
	         //document.write("URL changed is "+big5URL+" 3<br>");
	         //document.write("linkText is "+linkText+" 3<br<br>>");
	         //document.write("imgURL  changed is "+imgURL+" 3<br>");
	    }
	   else if(curURL.match(gateRegExp)!=(null||undefined))
	   {
	         big5URL=curURL.replace(/http:\/\/big5.lrn.cn\/gate\/big5\//,"http://")+RegExp.$3;
	         linkText=chineseLinkText;
	         imgURL=imgURLBase+chineseImgFile;
	         
	         //document.write("URL changed is "+big5URL+" 4<br>");
	         //document.write("linkText is "+linkText+" 4<br><br>");
	         //document.write("imgURL  changed is "+imgURL+" 4<br>");

	    }
       

	   //document.write("URL changed is "+big5URL+" <br>");
	   //document.write("linkText is "+linkText+" 4<br><br>");
	   //document.write("imgURL  changed is "+imgURL+" <br>");

	    if(big5URL!=undefined)
	   {
	        //document.write("URL changed is "+big5URL+" <br>");
	        //document.write("linkText is "+linkText+" <br>");
	        //document.write("imgURL  changed is "+imgURL+" <br>");

           var curLinkStartTag="<a "+"href="+"'"+big5URL+"'>";
           var curLinkEndTag="</a>";
	       var chineseToBig5ImgTag="<img "+"src="+imgURL+" border='0'  width='94' height='18'>";
	       
	       document.write(curLinkStartTag);
	       //document.write("<strong><font color='#BB0000'>");
	       //document.write(linkText);
	       //document.write("</font></strong>");
	       document.write(chineseToBig5ImgTag);
	       document.write(curLinkEndTag);
	   }
						
}