{“error”: “Please use POST request”} – alternative solution to submitting a form

I’m working on a school project and have attempted to create a calculator that can be found at the following link:

http://jsfiddle.net/ae97vgxz/2/

And my JS is:

$(document).ready(function(){

// Setup variable as empty
var method = "";

// Detect when initial radio button is clicked
$("input[type=radio]").click(function() { 

    // Get the weight from the input box
    var weight = $("#meatWeight").val();

    // If the water method was clicked
    if ($(this).hasClass("water")) {
        var method = weight * 60;
        // Show me what the value is (can be removed)
        alert(method);

    // If the fridge method was clicked
    } else if ($(this).hasClass("fridge")) {
        var method = weight * 793;
        // Show me what the value is (can be removed)
        alert(method);
    }
});

When you use it, if you enter a weight first, then select a method of defrosting you will get the correct answer in an alert window. However, if you press the ‘calculate’ button you get the following message –

{"error": "Please use POST request"}

From doing some of my own research, I believe this is because I am trying to submit a form and JSFiddle doesn’t let you do that. If I try on a local environment in Chrome, again there is no output.

I am very limited by my JS knowledge (as I’m sure you can see) so I just can’t fathom out a solution. Can anyone suggest what I am doing wrong and what the solution might be?

Thanks!