How to fix MoDX error?

Question

MODX

Mistake:

Error : Uncaught Error: Call to undefined function mysql_num_rows() in /home/h/hotelbeta/public_html/manager/includes/document.parser.class.inc.php(1965) : eval()'d code:18
Stack trace:
#0 /home/h/hotelbeta/public_html/manager/includes/document.parser.class.inc.php(1965): eval()
#1 /home/h/hotelbeta/public_html/manager/includes/document.parser.class.inc.php(2116): DocumentParser->evalSnippet('$idd = $modx->d...', Array)
#2 /home/h/hotelbeta/public_html/manager/includes/document.parser.class.inc.php(2028): DocumentParser->_get_snip_result('slider')
#3 /home/h/hotelbeta/public_html/manager/includes/document.parser.class.inc.php(2718): DocumentParser->evalSnippets('parseDocumentSource('prepareResponse()
#6 /home/h/hotelbeta/public_html/index.php(139): DocumentParser->executePa

The code itself, which swears:

<?php
$idd = $modx->documentIdentifier;

$res = $modx->getDocumentChildren(
    $id = 207,
    $active = 1,
    $deleted = 0,
    'id, menutitle',
    $where = 'hidemenu = 0',
    $sort='menuindex',
    $dir='asc',
    $limit
);
$i=1;

foreach($res as $key => $value) {
    $quer="SELECT*FROM modx_site_tmplvar_contentvalues where tmplvarid=59 and contentid=".$value[id];
        $res=MYSQL_QUERY($quer);
        if (mysql_num_rows($res)==0) { $img="";}
        else
        {
        @$v=mysql_fetch_assoc($res);
        @$v[value]=substr ( $v[value], 1 );
        @$size = getimagesize ($v[value]);
        @$w=$size[0]; $h=$size[1];
        echo "<img src=\"[(base_url)]$v[value]\" width=\"$w\" height=\"$h\" alt=\"\" />";
        }
}