dbmopen(%synusers,"synusers",0666) || die "Can't open synusers DBM fil
+e\n";
    #search database entries
    while (($key, $value) = each(%synusers)){
        if (index($key,$fields{'updalumname'})!=-1){
             ($alumemail, $emailpub, $alumsnail1, $snail1pub, $alumsna
+il2, $snail2pub, $alumsnail3, $snail3pub, 
            $phone, $phonepub, $alumyears, $yearspub, $comment, $comme
+ntpub, $synpass, $synpass2)=split(/::/,$value);
        
            if ($fields{'synpassold'} ne $synpass2){
                print "Content-type: text/html", "\n\n";
                print "Incorrect password.  If you cannot remember you
+r old password, email the webmaster.";
                die;
            }
            
            if ($fields{'updsynpass'}==""){
                $fields{'updsynpass'}=$synpass2;
                $fields{'updsynpass2'}=$synpass2;
            }
            delete $synusers{$fields{'updalumname'}};
            $synusers{$fields{'updalumname'}}="
            $fields{'updalumemail'}::$fields{'updemailpub'}::
            $fields{'updalumsnail1'}::$fields{'updsnail1pub'}::$fields
+{'updalumsnail2'}::$fields{'updsnail2pub'}::
            $fields{'updalumsnail3'}::$fields{'updsnail3pub'}::$fields
+{'updphone'}::$fields{'updphonepub'}::$fields{'updalumyears'}::$field
+s{'updyearspub'}::
            $fields{'updcomment'}::$fields{'updcommentpub'}::$fields{'
+updsynpass'}::$fields{'updsynpass2'}";
        
            print "Content-type: text/html", "\n\n";
            print "Thank you for updating your information.";
            die;
        }
    }
[download]

dbmopen

Consider using a tied hash instead.

print "Content-type: text/html", "\n\n";

You can add the \n\n in the first literal string.

die;

You shouldn't die unless a real error occurs. Bad user input is not considered a program error, so it should not output to STDERR (everything that is output to STDERR is appended to the error log of the webserver). Consider using exit instead.

if ($fields{'updsynpass'}==""){

Don't use == for string comparison. Use the string equality test operator eq instead.

$fields{'updalumemail'}::$fields{'updemailpub'}:: $fields{'updalumsnail1'}::$fields{'updsnail1pub'}::$fields{'updalums +nail2'}::$fields{'updsnail2pub'}:: $fields{'updalumsnail3'}::$fields{'updsnail3pub'}::$fields{'updphone +'}::$fields{'updphonepub'}::$fields{'updalumyears'}::$fields{'updyearspub'}:: $fields{'updcomment'}::$fields{'updcommentpub'}::$fields{'updsynpass +'}::$fields{'updsynpass2'}"

Ouch. Consider using join instead. That would also fix your original %09-character problem. join is the exact opposite of split.

$synusers{ $fields{updalumname} } = join '::', 
    @fields{qw(updalumemail  updemailpub   updalumsnail1 updsnail1pub
               updalumsnail2 updsnail2pub  updalumsnail3 updsnail3pub
               updphone      updphonepub   updalumyears  updyearspub
               updcomment    updcommentpub updsynpass    updsynpass2)}
+;
[download]

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

THANKS for the tips. Very helpful. Considered tie before but will give it more thought now. Also will try the join. Didn't realize hadn't replaced == with eq (teaching myself perl these past months when I have free time). Will try this stuff this week.