JavaScript环境中 实现GB2312 与 UTF8 之间的转码

<script language="javascript">
 function gb2utf8(data)
 {
    var glbEncode = [];
    gb2utf8_data = data;
    execScript("gb2utf8_data = MidB(gb2utf8_data, 1)", "VBScript");
    var t = escape(gb2utf8_data).replace(/%u/g,"").replace(/(.{2})(.{2})/g,"%$2%$1").replace(/%([A-Z].)%(.{2})/g,"@$1$2");
    t = t.split("@");
    var i = 0, j = t.length, k;
    while( ++i < j )
    {
       k = t[i].substring(0,4);
       if(!glbEncode[k])
       {
          gb2utf8_char = eval("0x"+k);
          execScript("gb2utf8_char = Chr(gb2utf8_char)", "VBScript");
          glbEncode[k] = escape(gb2utf8_char).substring(1,6);
       }
       t[i] = glbEncode[k]+t[i].substring(4);
    }
    gb2utf8_data = gb2utf8_char = null;
    return unescape(t.join("%"));
 }
 
 function utf8(wide)
 {
   var c, s;
   var enc = "";
   var i = 0;
   while(i<wide.length)
   {
   c= wide.charCodeAt(i++);
   // handle UTF-16 surrogates
   if (c>=0xDC00 && c<0xE000) continue;
   if (c>=0xD800 && c<0xDC00)
   {
      if (i>=wide.length) continue;
      s= wide.charCodeAt(i++);
      if (s<0xDC00 || c>=0xDE00) continue;
      c= ((c-0xD800)<<10)+(s-0xDC00)+0x10000;
   }
   // output value
   if (c<0x80)
      enc += String.fromCharCode(c);
   else if (c<0x800)
      enc += String.fromCharCode(0xC0+(c>>6),0x80+(c&0x3F));
   else if (c<0x10000)
      enc += String.fromCharCode(0xE0+(c>>12),0x80+(c>>6&0x3F),0x80+(c&0x3F));
   else
      enc += String.fromCharCode(0xF0+(c>>18),0x80+(c>>12&0x3F),0x80+(c>>6&0x3F),0x80+
  
   (c&0x3F));
   }
   return enc;
 }
 
 var hexchars = "0123456789ABCDEF";  

 function toHex(n)
 {  
   return hexchars.charAt(n>>4)+hexchars.charAt(n & 0xF);  
 }
 
 var okURIchars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-";
  
 function encodeURIComponentNew(s)
 {  
  var s = utf8(s);  
  var c;  
  var enc = "";  
  for(var i= 0; i < s.length; i++)
  {  
  if(okURIchars.indexOf(s.charAt(i))==-1)  
     enc += "%"+toHex(s.charCodeAt(i));  
  else  
     enc += s.charAt(i);  
  }  
  return enc;  
 }

 function TestDEMO()
 {
  var s2 ="中国医科大学";
  var f2 = encodeURIComponentNew(s2); 
  alert(f2);
   }
 </script>