arthemg

It throws an error: Uncaught #<Object> sphere.js:6 assert sphere.js:6 calculate sphere.js:21 I'm trying to figure it out, searching the web, but I can't seem to figure out the solution.

Hello, I am new to the programming and javascript and I have a question. I can not figure out how to get assertion function to work. I tried it with the sphere.js that is included with the book but it does not work. once I run the code nothing happens, but if I comment out the radius assertion it works fine. Thanks for the help. //script function assert(expression, message) { if (!expression) throw { name: 'Assertion Exception', message: message}; } function calculate() { 'use strict'; // For storing the volume: var volume; // Get a reference to the form value: var radius = document.getElementById('radius').value; assert((typeof radius == 'number'), 'The radius has to be a number.'); // Perform the calculation: volume = (4/3) * Math.PI * Math.pow(radius, 3); assert(!isNaN(volume), 'The volume is not a number'); // Format the volume: volume = volume.toFixed(4); // Display the volume: document.getElementById('volume').value = volume; // Return false to prevent submission: return false; } // End of calculate() function. // Function called when the window has been loaded. // Function needs to add an event listener to the form. function init() { 'use strict'; document.getElementById('theForm').onsubmit = calculate; } // End of init() function. window.onload = init;