dennispipper/ch2_mpg.html

## ch2_mpg.html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
	<title>Calculate Miles Per Gallon</title>
   	<script src="http://html5shiv.googlecode.com/svn/trunk/html5.js">
    // for versions IE 6-8
    </script>
   	<script>
        //create a loop that gets the miles and checks that it is a number

        do {
        //create a var named miles from the suer prompt box

        	var miles = prompt("Enter miles driven");
        //convert the miles var contents to a number
        	miles = parseFloat(miles);
            //check to make sure it is a number and is more than zero
        	if (isNaN(miles) || miles <= 0) {
        		alert("Miles must be a number greater than zero");
        	}
        }
        //the while portion of the do-while loop, executes as long as the do is true
        while (isNaN(miles) || miles <= 0);
        //get input from user in a prompt box
        do {
        	var gallons = prompt("Enter gallons of gas used");
            //convert the string to a number
        	gallons = parseFloat(gallons);
            //checking for valid values
        	if (isNaN(gallons) || gallons <= 0) {
        		alert("Gallons must be a number greater than zero");
        	}
        }
        while (isNaN(gallons) || gallons <= 0);
        //create a variable that divides miles/gallons
		var mpg = miles/gallons;
        //converts it to a number
		mpg = parseInt(mpg);
        //alerts the user the results
		alert("Miles per gallon = " + mpg);
    </script>
</head>
<body>
    <section>
        <h1>This page is displayed after the JavaScript is executed</h1>
    </section>
</body>
</html>
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>Calculate Miles Per Gallon</title>
	<script src="http://html5shiv.googlecode.com/svn/trunk/html5.js">
	// for versions IE 6-8
	</script>
	<script>
	//create a loop that gets the miles and checks that it is a number

	do {
	//create a var named miles from the suer prompt box

	var miles = prompt("Enter miles driven");
	//convert the miles var contents to a number
	miles = parseFloat(miles);
	//check to make sure it is a number and is more than zero
	if (isNaN(miles) \|\| miles <= 0) {
	alert("Miles must be a number greater than zero");
	}
	}
	//the while portion of the do-while loop, executes as long as the do is true
	while (isNaN(miles) \|\| miles <= 0);
	//get input from user in a prompt box
	do {
	var gallons = prompt("Enter gallons of gas used");
	//convert the string to a number
	gallons = parseFloat(gallons);
	//checking for valid values
	if (isNaN(gallons) \|\| gallons <= 0) {
	alert("Gallons must be a number greater than zero");
	}
	}
	while (isNaN(gallons) \|\| gallons <= 0);
	//create a variable that divides miles/gallons
	var mpg = miles/gallons;
	//converts it to a number
	mpg = parseInt(mpg);
	//alerts the user the results
	alert("Miles per gallon = " + mpg);
	</script>
	</head>
	<body>
	<section>
	<h1>This page is displayed after the JavaScript is executed</h1>
	</section>
	</body>
	</html>