problem in merging the files

hi friends,

I've coded a file merging program in C. though, the program seems to work far upto as how it supposed to but there is a problem.
when i tried to merge few media files to make it a whole in one then i got its size desirable equal to the sum of all ones though but I didn't get it played anyway.

Code:

#include<stdio.h>
#include<string.h>

char buffer[BUFSIZ];
main()
 {
      FILE *fsource,*fdest; char dirpath[30],sourcepath[40],destpath[40];
      int files=0,count;
      clrscr();
    // input directory

      printf("enter the full path of directory the content of which is to reconcile\n");
      gets(dirpath);

      printf("\nenter the number of files stored in this directory");
      scanf("\n%d",&files);
      strcpy(destpath,dirpath);
      strncat(destpath,"movie.flv",9);

      fdest=fopen(destpath,"wb");
      setvbuf(fdest,buffer,_IOFBF,BUFSIZ);
      fseek(fdest,0L,1);
      

      for(count=1;count<=files;count++)
	{
	  sprintf(sourcepath,"%s%d%s",dirpath,count,".flv");

	  fsource=fopen(sourcepath,"rb");
	  fseek(fsource,0L,1);
	  setvbuf(fsource,buffer,_IOFBF,BUFSIZ);
	  printf("\npart %d is being processed",count);

	  while(fread(buffer,BUFSIZ,1,fsource))
	    { 
              
	       fseek(fsource,BUFSIZ,1);
	       fwrite(buffer,BUFSIZ,1,fdest) ;
	       
	       fseek(fdest,BUFSIZ,1);
	    }
	   printf("\npart %d is processed",count);
	}


 }

please someone nail out the problem

 

please someone check this out