missing ) after argument ajax.updater

Aiiiii. The code is lovely but it only does the decrement for the back button twice. I'm at a loss. How can I get that php code at the top to check $paintingBack more than twice? I would appreciate any help. Thank you.

Here's the code:

<?php
    $paintingBack=$paintingNumber-1;
    $paintingNext=$paintingNumber+1;
    if ($paintingBack < 1) {
    $paintingBack = $paintingBack + 1;
    }
    ?>
    <a href="" id="link1" class='link'><img src='images/braceL.gif' alt='brace' width='20' height='11' valign='text-bottom'/></a>
	<script type="text/javascript">
	var l = document.getElementById("link1");
	l.onFocus = function() {
    if(this.blur)this.blur();
	}
	l.onclick = function() {
    document.getElementById("paintingImage").innerHTML = "<img src='images/painting_<? echo $paintingBack; ?>.jpg' />";
    return false;
	}
	</script>
     <a href="thumbnails.php" class="linkCurrent" target="_self" onFocus="if(this.blur)this.blur)" />PAINTINGS</a>
     <a href="painting_<?php echo $paintingNext; ?>.php" class="link" target="_self" onFocus="if(this.blur)this.blur()" /><img src="images/braceR.gif" alt="brace" width="20" height="14" valign="text-bottom" onFocus="if(this.blur)this.blur()" /></a>

Code (markup):

 

What I need to do is loop through this code.

	<?php
    $paintingBack=$paintingNumber-1;
    $paintingNext=$paintingNumber+1;
    if ($paintingBack < 1) {
    $paintingBack = $paintingBack + 1;
    }
    ?>
    <a href="" id="link1" class='link'><img src='images/braceL.gif' alt='brace' width='20' height='11' valign='text-bottom'/></a>
	<script type="text/javascript">
	var l = document.getElementById("link1");
	l.onFocus = function() {
    if(this.blur)this.blur();
	}
	l.onclick = function() {
    document.getElementById("paintingImage").innerHTML = "<img src='images/painting_<? echo $paintingBack; ?>.jpg' />";
    return false;
	}
	</script>

Code (markup):