php code to make a fieldset invisible in html page - php

Question

I have a fieldset in the html page.I need the field set to be invisible during a specific radio button click.
$cat is the radiobutton name,Dessert is the value.This radio button is inside the field set
The following code does not work.
How to do this through php code.I don't need to be done with javascript or jquery.
Here is the Code :
<?
if((!empty($cat) && $cat==="Dessert"))
{
echo "<fieldset id='typeradio' hidden='hidden'>";
echo"success";
} >?
How can i do this ?

Answer 1

You can disable it if you don't want it to work
<fieldset id="typeradio" disabled>
or hide it using CSS
<fieldset id="typeradio" style="display: none;">

Answer 2

Try This
It will only work if you post back your page and set the $cat property there otherwise you will have to do it via Jquery or JavaScript or ajax request. By post back i mean full page reload and server will do all checks and apache server will generate Html for this if condition
<?
if((!empty($cat) && $cat==="Dessert"))
{
echo "<fieldset id='typeradio' style='display:none'>";
echo"success";
} >?

Answer 3

//this example.php
<?
if(isset($_POST['opt'])){
$cat=$_POST['opt'];
if($cat==="Dessert")
{
echo "<form name="frm" action='example.php' method="post"><fieldset id='typeradio' hidden='hidden'><input type='radio' name='opt' value="Dessert" onclick="this.form.submit();"></fieldset></form>";
echo"success";
}
}
else
{
echo "<form name="frm" action='example.php' method="post"><fieldset id='typeradio' ><input type='radio' name='opt' value="Dessert" onclick="this.form.submit();"></fieldset></form>";
}
>?

Answer 4

//there was some quotes mistakes in previous code try this
<?php
if(isset($_POST['opt'])){
$cat=$_POST['opt'];
if($cat==="Dessert")
{
echo "<form name='frm' action='example.php' method='post'><fieldset id='typeradio' hidden='hidden'><input type='radio' name='opt' value='Dessert' onclick='this.form.submit();'></fieldset></form>";
echo"success";
}
}
else
{
echo "<form name='frm' action='' method='post'><fieldset id='typeradio' ><input type='radio' name='opt' value='Dessert' onclick='this.form.submit();'></fieldset></form>";
}
?>