1<!DOCTYPE html>
2<html lang="en">
3<head>
4 <meta charset="UTF-8">
5 <meta http-equiv="X-UA-Compatible" content="IE=edge">
6 <meta name="viewport" content="width=device-width, initial-scale=1.0">
7 <title>Document</title>
8</head>
9<body>
10 <form action="" method="post">
11 <h1>ISSET Demo</h1>
12 <input type="submit" value="Click here" name="btn1">
13 </form>
14</body>
15</html>
16<?php
17if(isset($_POST['btn1']))
18{
19 echo "button was set!";
20}
21?>