Create a two-part form that calculates and displays the amount of a Salespersons , salary based on the amount of sales and the commision rate that you input. Use an HTML document named salary.html as a web form with 2 text boxes-one for the amount of sales and one for the commission rate rate. Use a PHP document name salary.php as the form handler. Be sure to verify and validate the submitted form data and provide appropriate error messages for invalid values.