Script from HTML form help required

mos5 · 01-20-2013, 01:27 PM

Hello,

I am trying to create a javascript function (Please see the function below) which calculates the total cost of a trip for three different vehicles based on html form input (Please see HTML code below) but I cannot get the script to work. Any help would be appreciated.

Here is the HTML code:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<link rel="stylesheet" type="text/css" href=".css" />

<script type="text/javascript" src="C:\Users\ME\Desktop\Lab3.js">
</script>
<title>Calculating with JavaScript and HTML Forms</title>
</head>
<body>
<noscript>
<h2>This page requires JavaScript</h2>
</noscript>

<img src="C:\Users\ME\Desktop\logoSML.bmp" alt="logo" width="400" />
<p> In this lab lets look at some additional things that JavaScript
can do, such as make calculations with user input from a form. </p>

<h2>The Problem: </h2>

<p>I want to take a drive from Colorado Springs to
Yellowstone Park. The reported distance is 638 miles. I would like to know
how much the fuel is going to cost me to make this round trip. I have three options
for my transportation....Assume that gas costs on averate $2.33 per gallon.</p>

<ol>
<li>My Car that gets on average 19mpg...</li>
<li>My Motorcycle that gets on average 76 mpg...</li>
<li>My Friends hybrid that gets on average 48mpg</li>
</ol>
<br />

<p> Fill in the form items below to get the input necessary to make the calculations: </p>

<p> <label>Distance to be traveled: <input type="text" size = "8" name="distance"
id="dist" /></label></p>
<p> <label>MPG for My Car: <input type="text" size = "8" name="mycarMpg"
id="mycarMPG" /></label></p>
<p> <label>MPG for Motorcycle: <input type="text" size = "8" name="mtrcycMpg"
id="mcmpg" /></label></p>
<p> <label>MPG for the Hybrid: <input type="text" size = "8" name="hybridMpg"
id="hmpg" /></label></p>

<div>
<input type="button" value="Calculate the cost for each vehicle"
onclick="CalculateCost();"/>
</div>

<br /> <br />
<table align="center" border="3">
<tr>
<th>Cost with My Car</th>
<th>Cost with Motorcycle</th>
<th>Cost with Hybrid</th>
</tr>
<tr>
<td id="mycar">&nbsp</td>
<td id="mtrcyc">&nbsp</td>
<td id="hybrid">&nbsp</td>
</tr>
</table>

</body>
</html>

Here is my attempt at the script:

function CalculateCost(){
var dist = document.getElementById("dist").value;
var mycarMpg = document.getElementById("mycarMpg").value;
var mtrcycMPG = document.getElementById("mtrcycMpg").value;
var hybridMpg = document.getElementById("hybridMpg").value;

var mycar = document.getElementById("mycar").value;
var mtrcyc = document.getElementById("mtrcyc").value;
var hybrid = document.getElementById("hybrid").value;

mycar = dist/mycarMpg*2.33;
mycar = Math.round(mycar * 100)/100;

mtrcyc = dist/mtrcycMPG*2.33;
mtrcyc = Math.round(mtrcyc * 100)/100;

hybrid = dist/hybridMpg*2.33;
hybrid = Math.round(hybrid * 100)/100;
}

sunfighter · 01-22-2013, 12:19 AM

Code:

var mtrcycMPG = document.getElementById("mtrcycMpg").value;
var hybridMpg = document.getElementById("hybridMpg").value;

Should Be:

Code:

var mtrcycMPG = document.getElementById("mcmpg").value;
var hybridMpg = document.getElementById("hmpg").value;

Your IDs.
---------------------------------------------------------------------

These are not needed. It's where the answers go.

Code:

var mycar = document.getElementById("mycar").value;
var mtrcyc = document.getElementById("mtrcyc").value;
var hybrid = document.getElementById("hybrid").value;

Your math is wrong. You multiply first than divide. So your missing parentheses (). It's mycar = (dist/mycarMpg)*2.33;
Save some time and use (dist*2.33)/mycarMpg. (dist*2.33) is a constent and can be used in all calculations.

K = 638 * 2.33 = 1,486.54
so mycar = 1,486.54/mycarMpg;same for mtrcyc and hybrid.

And put the lines in to write your output.