Script Decimal To Octal for PHP

<?php
if (isset($_POST['decimal'])) {
    $des = $_POST['decimal'];
    $original = $_POST['decimal'];
    $oct ='';
    if (preg_match('/[^0-9]/',$des)){
        die("Maaf. Inputan salah..");
    }
else {
    while($des>0){
        $hasil=$des%8;
        switch($hasil){
            case 0: $oct.="0"; break;
            case 1: $oct.="1"; break;
            case 2: $oct.="2"; break;
            case 3: $oct.="3"; break;
            case 4: $oct.="4"; break;
            case 5: $oct.="5"; break;
            case 6: $oct.="6"; break;
            case 7: $oct.="7"; break;
            case 8: $oct.="10"; break;
            case 9: $oct.="11"; break;
            case 10: $oct.="12"; break;
            case 11: $oct.="13"; break;
            case 12: $oct.="14"; break;
            case 13: $oct.="15"; break;
            case 14: $oct.="16"; break;
            case 15: $oct.="17";
            default:break;           
        }

Script Decimal To Hexa for PHP

<?php
if (isset($_POST['decimal'])) {
    $des = $_POST['decimal'];
    $original = $_POST['decimal'];
    $hexa ='';
    if (preg_match('/[^0-9]/',$des)){
        die("Maaf. Inputan salah..");
    }
else {
    while($des>0){
        $hasil=$des%16;
        switch($hasil){
            case 0: $hexa.="0"; break;
            case 1: $hexa.="1"; break;
            case 2: $hexa.="2"; break;
            case 3: $hexa.="3"; break;
            case 4: $hexa.="4"; break;
            case 5: $hexa.="5"; break;
            case 6: $hexa.="6"; break;
            case 7: $hexa.="7"; break;
            case 8: $hexa.="8"; break;
            case 9: $hexa.="9"; break;
            case 10: $hexa.="A"; break;
            case 11: $hexa.="B"; break;
            case 12: $hexa.="C"; break;
            case 13: $hexa.="D"; break;
            case 14: $hexa.="E"; break;
            case 15: $hexa.="F";
            default:break;           
        }