error when $_POST is not present

[snowweb]

How can I get over the error when an expected variable is not passed in the URL?
In my script I have 2 variables, either of which may be passed in the url or none at all.
The page is capable of rendering without them except an error is producted "undefined index
in ProdID.
Here is the part causing the problem:

 if ($_REQUEST)
    {
    $ProdID = $_REQUEST['ProdID']; 

The trouble is that $_REQUEST may be true without 'ProdID' having been passed as it may be
true due to the other variable being passed.
I need to be able to say:
If $REQUEST contains 'ProdID' (regardless of whether anyother elements are present), then {}
Thanks in advance
pete

[vinyl-junkie]

Here is a better way of coding that:

$ProdID = $_REQUEST['ProdID']; 

if ($ProdID = "") {
   //error logic here 
} else {
  // normal processing
}

[snowweb]

Here is a better way of coding that:

$ProdID = $_REQUEST['ProdID']; 
 
if ($ProdID = "") {
   //error logic here 
} else {
  // normal processing
}

Thanks. I tried that though and it was saying that there was an error on

$ProdID = $_REQUEST['ProdID']; 

because $_REQUEST['ProdID'] was not present.
However, I eventually found the solution!
I used 'isset()' to determine whether the 'ProdID' was passed or not
Here's how I used it

<?
    if (isset($_REQUEST['deleted']))
      { 
         $deleted = $_REQUEST['deleted']; 
         echo "$deleted";
       }
?>

Thanks for your help.
peter

[HTML]

Thanks for letting us know how you finally solved the problem. I am sure others will find it of help.

Dave

[DeadMeatGF]

I tend to use the negative test ...

if (!$_REQUEST['ProdID']) {
   //error code goes here
   //exit script if required ...
}
$ProdID = $_REQUEST['ProdID'];
//Carry on with the page