Hi All, Thanks all of your help. The problem is solved after I disable

read(STDIN, $buffer,$ENV{'CONTENT_LENGTH'});
$buffer =~ tr/+/ /;
$buffer =~ s/\r/ /g;
$buffer =~ s/\n/ /g;
@pairs = split(/&/,$buffer);
foreach $pair(@pairs){
($key,$value)=split(/=/,$pair);
$formdata{$key}.="$value";
}
[download]

and change all the $formdata to param(). Last time I did changed to param without disable read(STDIN... Is my silly mistake. Thank you all of your advise. :) appreciated so much. At the end thank tobyink remind me to try param () again.