Working with forms?

[Perad]

I am trying to create a very simple script where I count the form entries and generate a total.

 

This is proving deceptively hard.

 

This is my form.

 

<div class="form_item">
<h3>Add a link to your website for $4</h3>
<input type="text" name="website" id="website" onchange="calculate()" value="<?php if (isset($_POST['website'])) { print $_POST['website']; } ?>"/>

<h3>Homepage</h3>
<p>Be on the homepage and be seen by hundreds of people</p>
<input type="checkbox" id="homepage" onchange="calculate()" name="homepage" <?php if (isset($_POST['homepage'])) { print 'CHECKED';} ?>> Home Page Ad (7 Days)


					<script type="text/javascript">
						var total = 0;
						function calculate()
						{
							document.write(document.calcform.website.value);		
						}

					</script>

	<h3>Category</h3>
	<p>Be the first thing users see when they enter your specified category.</p>
	<select name="duration" category onchange="calculate()">
		<option value="">None</option>
		<option value="3" <?php if (isset($_POST['duration']) == '3') { print 'selected="selected"'; } ?> >3 Days</option>
		<option value="7" <?php if (isset($_POST['duration']) == '7') { print 'selected="selected"'; } ?>>7 Days</option>
	</select>						
</div>

 

The forms name is called calcform.

 

Now what I am trying to do is as follows.

> If the website input has got someone thing in it then I want to set total variable to 4.

> If the homepage checkbox is ticked I want to add 20 to the total variable.

> If the category drop down is set I want I want to multiply 3 by the number of days in the select box.

 

I then need to be able to subtract from the total if the check box is unchecked. The category days are set to 0 and the website box is emptied.

 

Please.. can someone tell me how I can get the value for each of the 3 form fields. Once I know this I am sure that I can work out the rest myself.

[Northern Flame]

you can do something like:

 

<script type="text/javascript">
function checkFields(){
var website = document.forms['myForm'].website.value;
var homepage = document.forms['myForm'].homepage.value;
var duration = document.forms['myForm'].duration.value;

if(website == ""){
website = 0;
} else{
website = 4;
}

if(homepage == ""){
homepage = 0;
} else{
homepage = 20;
}

if(duration == ""){
duration = 0;
}

var total_value = website + homepage + duration;
}

// then on calculate() do something like this:
function calculate(){
var total = 100; // enter whatever you want the total to be
checkFields();
var new_total = total - total_value;
document.getElementById("showNewCalculations").innerHTML=new_total;
}
</script>
<form name="myForm">
<!--
put your form here
-->
Total: <span id="showNewCalculations"></span>
</form>