thanks to all
i make a function which solve the problem function is
function sreplace($string)
{
$patterns = "/'/";
$replacements = "''";
$string2= preg_replace($patterns, $replacements, $string);
return $string2;
}
$st="The 'quick brown fo'x jumped over' the la'zy do'g.";
$result=sreplace($st);
print $result;