compare two array, drop the duplicates, push to the arrayC :

print qq|<table><tr><td><br></td></tr>|;

for ($i=0; $i <=$#$array_ref; $i++){
#$ID = $array_ref->[$i][0];
$GN = $array_ref->[$i][0];
$Name = $array_ref->[$i][1];
print qq|<tr><td align="left" valign="top">
<a href="/cgi/cgi-shell/esp/iway/type/delete.pl?code=$code&typename=$Name">Delete</a> $Name</td></tr>|;
push @type, $Name; #get the list
}

print qq|<tr><td valign="top"><hr></td></tr>|;

ARRAY_A:
foreach my $x (@dropdownlist)
{
foreach (@type)
{
next ARRAY_A if $x =~ /^$_/;
}
push @ArrayC, $x;
} # compare two array, drop the duplicates, push to the arrayC


foreach $z(@ArrayC){
print qq|<tr><td><a href="/cgi/cgi-shell/esp/iway/type/add.pl?code=$code&typename=$z">Add</a> $z</td></tr>|;
}

print qq|</table>|;