      fprintf(textfile,"      if (%s_filename != NULL)\n",nameval);
      fprintf(textfile,"      {\n",nameval);
      fprintf(textfile,"         free(%s_filename);\n",nameval);
      fprintf(textfile,"      }\n",nameval);
      fprintf(textfile,"      %s_filename = (char *)malloc(strlen(\"%s.txt\")+1);\n",nameval,nameval);
      fprintf(textfile,"      strcpy(%s_filename,\"%s.txt\");\n",nameval,nameval);
