提示undefined 怎么处理
<?php
if(isset($_REQUEST['authcode'])){
session_start();
if(strtolower($_REQUEST['authcode']==$_SESSION['authcode'])){
echo '<font color = "#0000CC">输入正确</font>';
}else{
echo '<font color = "#CC0000"><b>输入错误</b></font>';
}
exit();
}
?>
提示是Notice: Undefined index: authcode in E:\wamp\www\yanzheng\form.php on line 4
