######################## presenters and companys, common, and common thing
for ($d=0; $d <=$#$array_ref; $d++){
$IDd = $array_ref->[$d][0];
$speakerd = $array_ref->[$d][1];
$companyd = $array_ref->[$d][2];
$OID = $array_ref->[$d][3];
if(($OID == 2)&&($companyd ne $companyd2)) { push @trycomp_list, $companyd; $companyd2=$companyd; }
}

$num=0;
foreach $trycomp(@trycomp_list){
$Snum=0;
for ($d=0; $d <=$#$array_ref; $d++){
$IDd = $array_ref->[$d][0];
$speakerd = $array_ref->[$d][1];
$companyd = $array_ref->[$d][2];
$OID = $array_ref->[$d][3];
if(($companyd eq $trycomp)&&($OID == 2)){
$Slist[$Snum]=$speakerd;
$Snum= $Snum +1;
}#if
}#for

if($Snum == 4){ $Clist[$num] = "$Slist[0], $Slist[1], $Slist[2], and $Slist[3], $trycomp";
} elsif ($Snum == 3){ $Clist[$num] = "$Slist[0], $Slist[1] and $Slist[2], $trycomp";
} elsif ($Snum == 2){ $Clist[$num] = "$Slist[0] and $Slist[1], $trycomp";
} elsif ($Snum == 1){ $Clist[$num] = "$Slist[0], $trycomp";
} else {}

$Slist[0]=""; $Slist[1]=""; $Slist[2]=""; $Slist[3]=""; $Snum=0; $Stexts ="";
$num= $num +1;
}#foreach

if($num == 4){ print qq|$Clist[0], $Clist[1], $Clist[2], and $Clist[3]<br><br>|;
} elsif ($num == 3){ print qq|$Clist[0], $Clist[1], and $Clist[2]<br><br>|;
} elsif ($num == 2){ print qq|$Clist[0] and $Clist[1]<br><br>|;
} elsif ($num == 1){ print qq|$Clist[0]<br><br>|;
} else {}

######################## presenter and company