如何根据使用单一表单选择的单选按钮修复代码以转到不同的页面

Question

I want to go to different templates(page) whatever is selected(radio button) from a single form. I want to include just one button in my form.

Here as if someone selects template1 I will to page template1.php. If I select template2 I will go to template2.php.

I have saved the below code as form.php

<form method="POST" action=
                          "<?php if(($rb = $_POST('template'))=='1'){?>
                                          template1.php 
                           <?php } 
                            if(($rb = $_POST('template'))=='2'){?>
                                          template2.php 
                            <?php } ?>"
                            enctype="multipart/form-data"> 
         <label>First Name: </label>
         <input type="text" name="firstname">
         <label>Last Name: </label>
         <input type="text" name="lastname">
         <input type="radio" value="1" name="template">Template 1
         <input type="radio" value="2" name="template">Template 2
         <button type="submit" name="upload">POST</button>      

  </form>