readwrite text in installshield

     #include "Ifx.h" 
       #define read_dir  "C:\\"
    #define read_file "read.txt"
     prototype readandwrite();
    
     function readandwrite()
  
    NUMBER nvFileHandle; 
    STRING szMsg; 
    
begin  
   
     OpenFileMode (FILE_MODE_APPEND);
    
     if (CreateFile (nvFileHandle, read_dir, read_file
) < 0) then
    
       // MessageBox (failed to create file, SEVERE);
       
     else
     
        szMsg = "hello god is watching u";
               
 
       
        if (WriteLine(nvFileHandle, szMsg) < 0) then
           
            MessageBox ("error", SEVERE);
        else
         
            SprintfBox (INFORMATION,  szMsg, read_file);
        endif;
    endif;
    CloseFile(nvFileHandle);
end;
///////////////////////////////////////////
  
   prototype readline();
    function readline()
    STRING  szFileName, szPath, szText, svLine;
    NUMBER  nFlag, nFileHandle;
    LIST   listID;
begin
   
 
    listID = ListCreate (STRINGLIST);
   
   
    OpenFileMode (FILE_MODE_NORMAL);
   
  
    OpenFile (nFileHandle,read_dir, read_file);
   
 
    while (GetLine (nFileHandle, svLine) = 0)
        ListAddString (listID, svLine, AFTER);
    endwhile;
   
   
    CloseFile (nFileHandle);
   
   
   SdShowInfoList ("", read_file, listID);
   
 
    ListDestroy (listID);
end;