[php: UA switch] attention on old code. #php

ua_switch.php

<php

/**
 * UA switch ( pc / sp )
 * <a href="hoge/index?ua=pc">DESKTOP</a>
 * <a href="hoge/index?ua=sp">MOBILE</a>
 */
  if (isset($_GET['ua'])) $_SESSION['ua'] = $_GET['ua'];
  if (isset($_SESSION['ua'])) {
    if($_SESSION['ua'] === "sp"){
    	// sp render
    }elseif($_SESSION['ua'] === "pc"){
    	// pc render
    }
  } else {
    $ua = $_SERVER['HTTP_USER_AGENT'];
    if (
		(strpos($ua,'iPhone')!==false)  || 
		(strpos($ua,'iPod')!==false)    || 
 		(strpos($ua,'Android')!==false) || 
		(strpos($ua,'Mobile')!==false)  ||
		(strpos($ua,'iPad')!==false)
	) {
  	  $_SESSION['ua'] = 'sp';
    } else {
  	  $_SESSION['ua'] = 'sp';
	}
  }