Create automatic A-Z page marker for the list of names using PHP

Create automatic A-Z page marker for the list of names using PHP

$lastName = ucfirst($row1->LastName);
$firstchar = $lastName{0};
//ucfirst ($firstchar);
if($previous!=$firstchar)
{
     $previous=$firstchar;
     echo "<h4><a name=\"$previous\">$previous</a></h4>";
     echo "<br>";
}