Php - testing if a radio button is selected and get the value

Question

I'm using php. I'd like to know how can I test if a radio button is selected and get the value? i can test if the radio button is selected but i cannot get the value. I created a button to test this in my form. First I select a radio button, then i click on the button and it must display a message that says which value i selected and put this value into a variable. In order to test if a radio button is selected i did like this:

$selected_radio=$_POST['SINGLE_' . $question->id . $multi_name_adjust . ''];
if ($selected_radio = 'checked'){}

Thanks

Answer 1

It's pretty simple, take a look at the code below:

The form:

<form action="result.php" method="post">
  Answer 1 <input type="radio" name="ans" value="ans1" /><br />
  Answer 2 <input type="radio" name="ans" value="ans2"  /><br />
  Answer 3 <input type="radio" name="ans" value="ans3"  /><br />
  Answer 4 <input type="radio" name="ans" value="ans4"  /><br />
  <input type="submit" value="submit" />
</form>

PHP code:

<?php 

$answer = $_POST['ans'];  
if ($answer == "ans1") {          
    echo 'Correct';      
}
else {
    echo 'Incorrect';
}          
?>