problems with isset within IF/THEN

[Ralph Arrar]

I'm building a URL based on data extracted from mySQL and I want the text space.gif used as my default value should the variable $picture by NULL.

The results of the code below kick back a value for $picture when it is set in the database, but ignores the space.gif if the database result is empty.

If I flip the test from ! isset to isset then I get the space.gif for each result.


I've had no luck searching out an answer.

Thanks in advance.

--------------The Code-----------------------------
<?php do { ?>
<img src="images/<?php
$picture=$row_rst_screenings['Picture'];

if(! isset($picture)) {
$picture='space.gif';
}else{
$picture=$row_rst_screenings['Picture'];
}

echo $picture;

?>"><br>
<p><span class="style2"><?php echo $row_rst_screenings['Title']; ?></span><br />
<span class="style3"><?php echo $row_rst_screenings['Director']; ?></span></p>
<p class="style4"><?php echo $row_rst_screenings['Blurb']; ?></p>
<p class="style3">Showtime: <?php echo $row_rst_screenings['ShowTime']; ?> <?php echo $row_rst_screenings['ShowDate']; ?></p>
<p class="style3">Location: <?php echo $row_rst_screenings['Location']; ?></p>

<?php } while ($row_rst_screenings = mysql_fetch_assoc($rst_screenings)); ?>

---------------END-----------------