PHP - Retrieve Information From Mysql Through Drop Down List

I'm doing this activity where a user chooses a base timezone and when the user clicks convert the current time in the selected GMT will be converted to GMT-11 to GMT+13.

As of now, I have these codes:
act09_view.php:
Code: [Select]
<?php
session_start();
    
    $s="GMT ";
    echo "Select the base time zone:</br>";
   
    for($n=-11;$n<=13;$n++)
    {
        if ($n>=0)
            $s="GMT +";
        $gmt[]=$s . $n . "</br>";
    }

    echo "<select name='gmt'>";
    foreach ($gmt as $value) 
    {
        echo '<option value="' . $value . '">' . $value . '</option>\n';
    } 
    echo '</select>';
    //$_SESSION['value']=$value;
 ?>
<form action="act09_process.php">
       </br><input type='submit' value='Convert'/>
</form>

act09_process.php:
Code: [Select]
<?php
session_start();
//$value=$_SESSION['value'];
//echo $value;

date_default_timezone_set('Asia/Manila');
$gmttime=date('M j, Y g:i:s A');
echo "The current date and time at" . " is " . $gmttime;
?>
I've tried using session variables. I think I executed them incorrectly. 

The output is supposed to look like this:

Hi,

Is it possible to retrieve all the information from a posted value without knowing the input field?

My page is taking information from a database and then creates a page with checkboxs so that people can select certain fields. There are 1300 fields in the database so I don't know what fields will be submitted when a person saves the page,  is there a simple way to check what fields have been submitted without writing a check for each checkbox?

I hope this makes sense, thanks in advance for any help.

I am working on a web application in php for ipad. I need to retrieve the ipad's unique identifier programmatically.
Is there any way i could check the unique identifier of an ipad in the php application.

I am working on a project that uses a drop down list to chose the category when inserting new data into the database. What I want to do now is make the drop down list default to the chosen category on the list records page and the update page. I have read several tutorials, but they all say that I have to list the options and then select the default. But since it is possible to add and remove categories, this approch won't work. I need the code to chose the correct category on the fly.

There are two tables, one that has the category ID and category name.  The second table has the data and the catid which is referenced to the category id in the first table.

Code: [Select]
--
-- Table structure for table `categories`
--

DROP TABLE IF EXISTS `categories`;
CREATE TABLE IF NOT EXISTS `categories` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `categories` varchar(37) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=40 ;

-- --------------------------------------------------------

--
-- Table structure for table `links`
--

DROP TABLE IF EXISTS `links`;
CREATE TABLE IF NOT EXISTS `links` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `catid` int(11) DEFAULT NULL,
  `name` varchar(255) NOT NULL DEFAULT '',
  `url` varchar(255) NOT NULL DEFAULT '',
  `content` varchar(255) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`),
  KEY `catid` (`catid`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=35 ;


Then is the list records file, I have

Code: [Select]
<?php
include ("db.php");
include ("menu.php");


$result = mysql_query("SELECT categories FROM categories") or die(mysql_error()); 
while ($row = mysql_fetch_array($result)) { 
$categories=$row["categories"];
$options.= '<option value="'.$row['categories'].'">'.$row['categories'].'</option>';
};



$id = $_GET['id'];
$query="SELECT * FROM links ORDER BY catid ASC";
$result=mysql_query($query);

?>
<table width="65%" align="center" border="0" cellspacing="1" cellpadding="0">
<tr>
<td>
<table width="100%" border="1" cellspacing="0" cellpadding="3">
<tr>
<td colspan="7"><strong>List data from mysql </strong> </td>
</tr>

<tr>
<td align="center"><strong>Category ID</strong></td>
<td align="center"><strong>Category ID</strong></td>
<td align="center"><strong>Name</strong></td>
<td align="center"><strong>URL</strong></td>
<td align="center"><strong>Content</strong></td>
<td align="center"><strong>Update</strong></td>
<td align="center"><strong>Delete</strong></td>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
?>
<tr>
<td>
<SELECT NAME=catid>
<OPTION>Categories</OPTION>
<?php echo $options; ?>
</SELECT>
</td>
<td><? echo $rows['catid']; ?></td>
<td><? echo $rows['name']; ?></td>
<td><a href="<? echo $rows['url']; ?>"><? echo $rows['url']; ?></a></td>
<td><? echo $rows['content']; ?></td>
<td align="center"><a href="update.php?id=<? echo $rows['id']; ?>">update</a></td>
<td align="center"><a href="delete.php?id=<? echo $rows['id']; ?>">delete</a></td>

</tr>
<?php
}
?>
</table>
</td>
</tr>
</table>
<?php
mysql_close();
?>

So, how do I get this code
Code: [Select]
$result = mysql_query("SELECT categories FROM categories") or die(mysql_error());
while ($row = mysql_fetch_array($result)) {
$categories=$row["categories"];
$options.= '<option value="'.$row['categories'].'">'.$row['categories'].'</option>';
};

<SELECT NAME=catid>
<OPTION>Categories</OPTION>
<?php echo $options; ?>
</SELECT>

to give me an output that will be

something like if catid exactly matches categories.id echo categories.categorie  ???

so far everything I have done produces either a default category of the last category,  the catid (which is a number), all of the categories (logical since catid will always be = id, or nothing.  How do I get just the category name? 

I will keep reading and try to figure this out, but any help would be greatly appreciated.

Thanks in advance

Hi

I have coded a drop down menu with php and i am trying to retrieve the data when a user select a option from the menu and the data is retrieved from the database. So far i have tried and nothing is displaying when i tried to process the php form.

Sales.php Page

<form action="saleprocess.php" method="GET">
<?php
echo 'Product Model:';
$query="SELECT * FROM products";
/* You can add order by clause to the sql statement if the names are to be displayed in alphabetical order */
$result = mysql_query ($query);
echo "<select name=product_model value=Select>Product Model</option>";
// printing the list box select command
while($rows=mysql_fetch_array($result)){//Array or records stored in $nt

echo "<option name=product_model value='.$rows[product_id].'>$rows[product_model]</option>";
/* Option values are added by looping through the array */
}
echo "</select><br>";
?>
<input type='submit' name='submit' value='Create'></input> <br>
</form>

********************************************************************************
Salesprocess.php page

<?php
include("connect.php");

if(isset($_GET['product_id'])){

$product_id = $_GET['product_id'];


$query = mysql_query("SELECT * FROM products WHERE product_id= $product_id");

while($rows = mysql_fetch_assoc($query))
{
echo 'Product Model<br>';
echo $rows['product_id'];
echo $rows['product_model'];


}
}
?>

Muchly appreciated if someone can help me