my $file = 'Events.txt';
open $info, "<", $file or die "Couldn't open events file: $!";
open $xml, "<", 'XML_FILE.xml' or die "Couldn't open xml file: $!";
open $output, ">", 'OUTPUT.txt' or die "Coudn't open output file: $!";
my $found = 0; #Flag for indication
while(my $line = <$info>)  {
    @get_data = split ',' ,$line;
    $alert_ID = $get_data[5];        

    seek $xml, 0, 0; # Seek to the beginning, to scan from beginning for each ID. 
    while(my $xml_line = <$xml>)  {
        if ($xml_line =~ m|<ALERT_ID>$alert_ID</ALERT_ID>|) {
            $found = 1; 
            last;
        }
    }
    if ( $found == 1 )  {
        print "$alert_ID Found.\n";
        $found = 0;
    }
    else  {
        print $output "@get_data";
    }
}

close $info;
close $xml;
close $output;