file i/o problem

[aman cgiperl]

I have a code that looks like the following

$pgs = 1000;
$lks = "Welcome Message";
for($i=0;$i<$pgs;$i++)    {
                open PGIN, "/$char/$mn/index_tmp".$i.".html";
                open PGOUT, ">/$char/$mn/index".$i.".html";
                while(<PGIN>)   {
                        $_ =~ s/##MSG##/$lks/g;
                        print PGOUT $_;
                }
close PGIN;
close PGOUT;

This code creates index pages from index_tmp pages. The problem is that the created 
pages are not complete. I mean the new pages don't have the complete html written from 
the index_tmp pages. This results some visible html code in IE and as expected, due to 
html error, nothing in Netscape.
Any suggestions?
Thank is advance.
Aman