este es el codigo completo el nombre del archivo es formulario_cotizacion.php
<?php
session_start();
?>
<?php
if(isset($_SESSION['k_username'])){
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Cotizacion</title>
<style type="text/css">
<!--
.Estilo1 {font-family: "Century Gothic"}
.Estilo2 {color: #FFFFFF}
.Estilo3 {font-family: "Century Gothic"; color: #FFFFFF; }
.Estilo4 {font-size: 24px}
-->
</style>
</head>
<body>
<?php include ('menu.php');?>
<form method="post" enctype="multipart/form-data" class="Estilo1" action="cotizacion.php">
<table width="80%" border="1" align="center" cellpadding="0" cellspacing="0">
<tr>
<td colspan="5" align="center" bgcolor="#000000"><span class="Estilo1 Estilo2">
<label></label>
</span><span class="Estilo1">
<label></label>
<span class="Estilo2 Estilo1"><strong><span class="Estilo4">DATOS DEL CLIENTE</span></strong></span></span></td>
</tr>
<tr>
<td width="20%" bgcolor="#000000"><span class="Estilo1 Estilo2"> Ciudad</span></td>
<td colspan="2" bgcolor="#000000"><input name="ciudad" type="text" id="ciudad" size="50" style="background-color: #F7F7F7;" /></td>
<td colspan="2" bgcolor="#000000"> </td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo1 Estilo2"> Empresa</span></td>
<td colspan="2" bgcolor="#000000"><input name="empresa" type="text" id="empresa" size="50" style="background-color: #F7F7F7;" /></td>
<td colspan="2" bgcolor="#000000"> </td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> NIT</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1">
<input name="nit" type="text" id="textfield3" size="50" style="background-color: #F7F7F7;" />
</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1"></span><span class="Estilo1"></span></td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> Cliente</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1">
<input name="cliente" type="text" id="textfield4" size="50" style="background-color: #F7F7F7;" />
</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1"></span><span class="Estilo1"></span></td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> Direccion</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1">
<input name="direccion" type="text" id="textfield5" size="50" style="background-color: #F7F7F7;" />
</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1"></span><span class="Estilo1"></span></td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> Telefono</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1">
<input name="telefono" type="text" id="textfield6" size="50" style="background-color: #F7F7F7;" />
</span></td>
<td colspan="2" bgcolor="#000000"><span class="Estilo1"></span><span class="Estilo1"></span></td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> Celular</span></td>
<td colspan="2" bgcolor="#000000"><input name="celular" type="text" id="textfield7" size="50" style="background-color: #F7F7F7;" /></td>
<td colspan="2" bgcolor="#000000"> </td>
</tr>
<tr>
<td bgcolor="#000000"><span class="Estilo3"> E-mail</span></td>
<td colspan="2" bgcolor="#000000"><input name="email" type="text" id="textfield8" size="50" style="background-color: #F7F7F7;" /></td>
<td colspan="2" bgcolor="#000000"> </td>
</tr>
<tr>
<td bgcolor="#666666"><span class="Estilo1"> </span><span class="Estilo3">Comentarios</span></td>
<td colspan="2" bgcolor="#666666"><textarea name="comentario" cols="50" id="textfield2" style="background-color: #F7F7F7;"></textarea></td>
<td colspan="2" bgcolor="#666666"> </td>
</tr>
<tr>
<td bgcolor="#F2F2F2"> </td>
<td colspan="2" bgcolor="#F2F2F2"> </td>
<td colspan="2" bgcolor="#F2F2F2"> </td>
</tr>
<tr>
<td bgcolor="#666666"> <span class="Estilo3">Adicionales</span></td>
<td width="33%" bgcolor="#F2F2F2"><textarea name="adicionales_descripcion" cols="50" id="comentario" style="background-color: #F7F7F7;"></textarea></td>
<td width="29%" bgcolor="#F2F2F2"><input name="adicionales_precio" type="text" id="textfield9" size="10" style="background-color: #F7F7F7;" /></td>
<td colspan="2" bgcolor="#F2F2F2"><input name="adicionales" type="text" id="textfield" size="10" style="background-color: #F7F7F7;" /></td>
</tr>
<tr>
<td colspan="5" align="center" bgcolor="#000000"><strong><span class="Estilo4"><span class="Estilo2">ELEMENTOS</span><BR >
</span></strong></td>
</tr>
<?php
include("conex.php");
$link=conectarse();
$result=mysql_query("select * from productos ORDER BY orden ASC ",$link);
?>
<?php
while($row = mysql_fetch_array($result)) {
?>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<tr>
<td bgcolor="#F2F2F2"><strong><?php echo $row['producto'];?></strong></td>
<td colspan="2" bgcolor="#F2F2F2"><span class="Estilo1"> </span><?php echo utf8_encode($row['descripcion']);?></td>
<td width="12%" bgcolor="#F2F2F2"><span class="Estilo1">
<input name="<?php echo $row['variable'];?>" type="text" id="textfield" size="10" style="background-color: #F7F7F7;"/>
</span> </td>
<td width="6%" bgcolor="#F2F2F2"> </td>
</tr>
<tr>
<td colspan="5" height="5" bgcolor="#ffffff"></td>
</tr>
<?php
}
?>
<tr>
<td colspan="5" align="right" bgcolor="#F2F2F2"><span class="Estilo1"></span><span class="Estilo1"></span><span class="Estilo1"></span><span class="Estilo1"></span><span class="Estilo1"></span><span class="Estilo1"></span><span class="Estilo1"></span> <label><br />
<input name="<?php echo $row['id'];?>" type="hidden" style="background-color: #F7F7F7;"/>
<input name="<?php echo $row['producto'];?>" type="hidden" style="background-color: #F7F7F7;"/>
<input name="<?php echo $row['precio'];?>" type="hidden" style="background-color: #F7F7F7;"/>
<input type="submit" name="button" id="button" value="Cotizar"/>
</label></td>
</tr>
</table>
</form>
</body>
</html>
<?php
}
?>