UNIX for Dummies Questions & Answers

I have the following nawk script:

nawk -F: '{ if($0 ~ "^Report No") {fl=1; i=0;}
if(fl==1){data[i]=$0; i++}
if($0 ~ "^BE NO:")
{
fname = "reprot_"$2".lis";
gsub(" ","",fname);
for(j=0;j<i;j++) print data[j] > fname;
fl=0;
}
else if(fl==0) print $0 > fname;
}' filename

When I try to apply it to split the big reports into smaller report, that is work fine. (the big report is start with "Report No" at the very begining)

However when I try to apply it to split the big report, that big report is start with few blank lines. I got the following error:

nawk: null file name in print or getline
input record number 1
source line number 9

The big report file is like the following (report.lis)
LINE # Report_code
1
2
3
4
5 Report No.: AAA
6
7 BE NO: 111
8
9 asfsdflsjdfklsdjfklsjfklsfsflsjdlk
10 fsdfjsfkjsklfsfj
11
12
13
14
15 Report No.: AAA
16
17 BE NO: 111
18
19 sdfsdfjsdklfjsfkj
20 fsdflkjsdfklsjkl
21
22
23
24
25 Report No.: AAA
26
27 BE NO: 222
28
29 dadaskdhasdjkd
30 dashdjkashdjhajkh
31
32
33
34
35 Report No.: AAA
36
37 BE NO: 222
38
39 dasdjaklsdjkladjkla
40 daskdjaskldjakldjklaj
41
42
43
44
45 Report No.: AAA
46
47 BE NO: 333
48
49 ddasdjaskldjkladjklasj
50 daskdjaskldjaskldj
51
52
53
54
55 Report No.: AAA
56
57 BE NO: 333
58
59 djakdadjaklsjdjak
60 dakdjakljdklajklsd
61
62
63
64
65 .................
66 .................
67 .................

my expected report result is like the following:
report_111.LIS
1
2
3
4
5 Report No.: AAA
6
7 BE NO: 111
8
9 asfsdflsjdfklsdjfklsjfklsfsflsjdlk
10 fsdfjsfkjsklfsfj
11
12
13
14
15 Report No.: AAA
16
17 BE NO: 111
18
19 sdfsdfjsdklfjsfkj
20 fsdflkjsdfklsjkl

report_222.LIS
21
22
23
24
25 Report No.: AAA
26
27 BE NO: 222
28
29 dadaskdhasdjkd
30 dashdjkashdjhajkh
31
32
33
34
35 Report No.: AAA
36
37 BE NO: 222
38
39 dasdjaklsdjkladjkla
40 daskdjaskldjakldjklaj

report_333.LIS
41
42
43
44
45 Report No.: AAA
46
47 BE NO: 333
48
49 ddasdjaskldjkladjklasj
50 daskdjaskldjaskldj
51
52
53
54
55 Report No.: AAA
56
57 BE NO: 333
58
59 djakdadjaklsjdjak
60 dakdjakljdklajklsd

Please help me, since I am a new baby in the Unix Script.....

Code:

nawk -F: 'BEGIN { b=1 }
{
   if (NF > 0 || b==0) {
      if ($0 ~ "^Report No") {b=0; fl=1; i=0;}
      if (fl==1) {data[i]=$0; i++}
      if ($0 ~ "^BE NO:") {
          fname = "report_"$2".lis";
          gsub(" ","",fname);
          for(j=0;j<i;j++) print data[j] > fname;
          fl=0;
      } else if (fl==0) print $0 > fname;
   }
}' filename