<?php    
class    timer    
{    
var    $time_start;    
var    $time_end;    

function    __construct()    
{    
$this->time_start    =    0;    
$this->time_end    =    0;    
}    

function    timer()    
{    
$this->__construct();    
}    

function    start()    
{    
list($usec,$sec)    =    explode("    ",microtime());    
$this->time_start    =    (float)$usec    +    (float)$sec;    
}    

function    stop()    
{    
list($usec,$sec)    =    explode("    ",microtime());    
$this->time_end    =    (float)$usec    +    (float)$sec;    
}    

function    show($output    =    false)    
{    
$total    =    $this->time_end    -    $this->time_start;    
if    ($output)    {    
echo    $total,"    sec";    
return    true;    
}    
return    $total."    sec";    
}    

}    
?>    
<?php    
echo    'check    prime<br/>';    
function    IsPrime($i)    
{    
if($i<2)    
{    
return    false;    
}    
//var    $iterator;    
for($iterator    =    2    ;    $iterator    <=    sqrt($i)    ;    $iterator++)    
{    
if($i    %    $iterator==0)    
{    
return    false;    
}    
}    
return    true;    
}    

$sw=new    timer();    
$sw->start();    
for($j=1;$j<100;$j++)    
{    
if(IsPrime($j))    
{    
echo    'true<br/>';    
}    
else    
{    
echo    'false<br/>';    
}    
}    
$sw->stop();    
$sw->show(true);    

?>