mb_ereg check string for UTF-8

Hi,
How can i check input string using mb_ereg? for UTF-8?
Thanks for help.

the example in the comments on PHP.net for this function seems like it might help?

PHP Code:

---

echo "Line "; 
if(mb_ereg(".*([א-ת]).*", $this->current_line))
{
    echo "has";
}
else
{
    echo "doesn't have";
}
echo " Hebrew characters.<br>"; 


---