simplexml_load_file problem

[shahrzad khorrami <shahrzad.khorrami@xxxxxxxxx>]

hi all,

$results is a xml format string,
I want to get this string as a real xml file
$nodes = simplexml_load_file($results);
but $nodes is empty array...
how can I do that?
nodes must be an object contains xml


Thanks,
Shahrzad Khorrami