Only use first 6 charcters in submitted field when parsing php

I have an input field that posts to this bit of php and works fine but i'd like users to be able to enter more than 6 characters into the input form and the开发者_Go百科n have the following only use the first 6 characters:

example: user enters: 1234567890 PHP (or javascript before the post) uses only "123456" and disregards "7890"

Here is the bit of php that's working as long as a user only enters 6 characters:

  ?php function getCode() {
 if (isset($_GET["code"])) {
   if ($_GET["code"] == "example1" || $_GET["code"] == "example1") {
    echo '<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.example.com">';
    } else if ($_GET["code"] == "example2" || $_GET["code"] == "example2") {
    echo '<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.example2.com">';
    } else if ($_GET["code"] != "example1" || $_GET["code"] != "example2") {
   //Looks like your lot number didn't work.
    $message =  '<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.example.com/noworky">';

   };
    return $message;
 };

Use the substr function to chop the input $_GET['code'] down to 6 characters, then compare that.

Why do you have all these redundantly duplicated conditions? And why the ; after the }s? I really recommend getting yourself a good book. Programming by guessing does not work [well].

$_GET["code"] = substr($_GET["code"],0,6);