How can I set a form select option to be selected?

[Kirsten Osa]

$select->find('option')->removeAttr('selected');  removes all the selected attributes for the currently selected $select (<select>)  but I am unable to set selected for an option

I have tried:

$option->attr('selected',true) does not appear to work.  It adds the selected attribute on the current $option but sets it to empty string. 

I have also tried :

$option->attr('selected',"selected") but it makes no difference. 

Using DOMDocument I can do the following:

$childNode->setAttribute('selected', 'selected'); 

but I can't find an equivalent option in queryPath.

Can anyone help?

[Kirsten Osa]

Please ignore as this does work.