There is an error in the lesson such that if the string position is found at the first index of the string id est 0 then the "if" statement will evaluate to false, even though the substring IS found..
Not very good to teach it like this
Replace this line with your code.
// Print out the position of a letter that is in
$myname = "Dogpaw";
print strpos($myname, "D");
// Check for a false value of a letter that is not
// in your own name and print out an error message
if (strpos($myname, "D") == false)
print "Sorry, no 'D' in the name";