When I ran it, it gave me error on line 23.

$value =~ s/+/ /;
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+ is just a quantifier, what is the object being quantified? I guess you mean:

$value =~ s/\s+/ /g;
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BTW, as you used the CGI module, why didn't you use CGI functions to generate html tags like "form"? try to use those functions to reduce malformated tags.