$re = '~(?<AttributeName>(?:src|background))\s*=\s*["\'](?<AttributeValue>(?:[^"\'])*)~';
$str = '<html>
<table id=\'tblTest\' border="1">
<tr>
<td colspan="1" >CellA</td>
</tr>
<tr>
<td>Click<a href="http://mail.google.com" >here</a></td>
</tr>
<tr>
<td>
<img src="http://wcrustine.org/Portals/0/click_here_button.jpg" style="width:100px;height:100px;"></img></td>
</tr>
<tr>
<td background="https://ci6.googleuser.com/proxy/d-NpaBfbly5hKSic8pomfvI4scwJqkF2wwmRqEB4stR8jfO7jo-Sx-JcVLfIXqw5gJnd05Rl0aY3evT2DhmS6he85ifLGQA=s0-d-e1-ft#http://newsletter.mydomain.com/template/header_bg.jpg" bgcolor="#336699" height="100" style="background:url(https://ci5.googleuser.com/proxy/d-NpaBfbly5hKSic8pomfvI4scwJqkF2wwmRqEB4stR8jJrvfO7jo-Sx-JcVLfIgJnd05Rl0aY3evT2DhmS6LU85ifLGQA=s0-d-e1-ft#http://newsletter.mydomain.com/template/header_bg.jpg) top left repeat #336699" width="">
</td>
</tr>
</table>
</html>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php