masih tetep gag bisa mas.
kode nama barangnya itu yang gag muncul di combo box-nya.
ini kode keseluruhan file dtlrc.php saya mas
<?php
require_once("libs/controller/Keluar.php"); 
$request = new Keluar();
$action = $_REQUEST['action'];
switch($action){
    case 'addNo':
    {
        $no_trjual = $_REQUEST['no'];
		$tanggal = $_REQUEST['tanggal'];
		$status = $_REQUEST['status'];
        $result = $request->addKeluar($no_trjual,$tanggal,$status);
        if($result === TRUE){
            echo "<font color='red'>(Insert berhasil)</font>";
        } else {
            echo $result;
        }
    } break;
    
    case 'delete':
    {
        $id = $_REQUEST['id'];
        $kd_barang = $_REQUEST['kd_barang'];
        $result = $request->deleteBarang($id,$kd_barang);
        if($result === TRUE){
            echo "<font color='red'>(Delete Berhasil)</font>";
        } else {
            echo $result;
        }
    } break;
	
	case 'addDtl':
	{
		$no_trjual = $_REQUEST['no'];
		$kd_barang = $_REQUEST['prdId'];
		$harga = $_REQUEST['harga'];
		$jml = $_REQUEST['jml'];
		
		$result = $request->addBarang($no_trjual,$kd_barang,$harga,$jml);	
		if($result === TRUE){
            echo "<font color='red'>(Insert berhasil)</font>";
            $_REQUEST['jml'] = "";
        } else {
            echo $result;
        }
	}
	case 'add':
    {
        $no = $_REQUEST['no'];
        $result = $request->addStock($no);
        if($result === FALSE){
            echo "  (<font color='red'> Barang Tidak Tersedia </font>)";
        }else{
            echo "  ";
        }
    } break;
    
    default:
}
?>
<style type="text/css">
<!--
.style1 {color: #FF0000}
.style2 {color: #009933}
-->
</style>
 <div id="main1">
<form method="POST" name="Form Request" action="index.php?page=dtlrc&action=addDtl"><br />
<label>No Penjualan</label>
<input class="text" type="text"  size="20" readonly="true" value="<?php echo $_REQUEST['no']; ?>" name="no"/><br />
<label>Nama Barang</label>
    <?php
    $saya = mysql_query("select * from barang");
    $jsArray = "var prdName = new Array();\n";
    echo '<select name="prdId" onchange="document.getElementById(\'harga\').value = prdName[this.value]">';
    echo '<option>-------</option>';
    while ($row = mysql_fetch_array($saya)) {
    echo '<option value="' . $row['id_barang'] . '">' . $row['namabarang'] . '</option>';
    $jsArray .= "prdName['" . $row['id_barang'] . "'] = '" . addslashes($row['hargajual']) . "';\n";
    }
    echo '</select>';
    ?>
    Harga: <input type="text" name="harga" id="harga"/>
    <script type="text/javascript">
    <?php echo $jsArray; ?>
    </script>
<label>Harga (Rp)</label>
<input class="text" type="text"  name="harga" readonly="true" value="<?php echo $_REQUEST['harga']; ?>" />
<br /><label>Jumlah</label>
<input class="text"  type="text" size="30" name="jml" value="<?php echo $_REQUEST['jml']; ?>" /><br>
<br />
<input class="button"  type="submit" name="tambah" value="Tambah" /><a href="?page=rc"><input class="button"  type="button" name="save" value="Save" />
</a>
</br>
</form>
</div><div id="main1">
<table border="0">
          <tr>
           	  	<th width="75">Nama</th>
            	<th width="50">Jumlah</th>
            	<th width="50">Harga</th>
            	<th width="50">Subtotal</th>
                <th width="50">Delete</th>
                                
          </tr>
            <?php 
			$no = $_REQUEST['no'];
			$id = $request->getId($no);
            $result = $request->showDtl($id);
            while($row = $result->fetch_assoc()){
				$sub=$row[jml]*$row[harga];
                echo "<tr>";
                echo "<td>$row[namabarang]</td>";
                echo "<td>$row[jml]</td>";
                echo "<td>Rp.$row[harga]</td>";
                echo "<td align='right'>Rp.$sub</td>";
                echo "<td class='act'><a href='index.php?page=dtlrc&action=delete&id=$row[id_trjual]&kd_barang=$row[kd_barang]&no=$row[no_trjual]&tanggal=$row[tanggal]'><img border='0' src='images/hapus.png'></a></td>";
                echo "</tr>";
				$total=$total+$sub;
            }
                echo "<tr><td align='right' colspan='4'>Total : Rp.$total</td></tr>";
            ?>
</table>
</div>