[PHP] How to use objects, variables in an eval() func ?

[LPA]

Hi,

I have an eval which evaluate a block of code before echo the result on the screen.. 
Here is the func :

function t_eval($texte) {
 ob_start();
  eval("?>".$texte);
  $retval = ob_get_contents();
 ob_end_clean();
 return $retval;
}

But I use some objects for databases, ... and when i trying to execute this code i 
have this text.
Fatal error: Call to a member function on a non-object in k:\program 
files\easyphp\www\dhea\include\php\functions_conversion.inc.php(23) : eval()'d code on 
line 9

What to do ?

Thanx 

Laurent