jquery change form button value in php - php

Question

I have a form with 2 dropdowns, 'Type' and 'Level', eg
Type
-----
Hotel
Restaurant
Casino
Level
-----
1
2
3
And a submit button which shows the price based on whichever options are selected in the dropdown. The price is calculated by some basic maths on the fly.
How can I do this using jquery?
Is it using onchange() or something?

Answer 1

$("#button_id_here").val("$your_amount_here");
If you want it to update automatically, bind it to the change event in the select/dropdowns
$("#select_id_here").change(function(){
//"basic maths"
$("#button_id_here").val("$your_amount_here");
});
You want more help, we would need to see code.

Answer 2

HTML:
<form>
<fieldset>
<p>
<label for="selectType">Type:</label>
<select id="selectType" name="type">
<option value="Hotel" data-cost="40">Hotel</option>
<option value="Restaurant" data-cost="80">Restaurant</option>
<option value="Casino" data-cost="35">Casino</option>
</select>
</p>
<p>
<label for="selectLevel">Level:</label>
<select id="selectLevel" name="level">
<option value="1" data-cost="0">1</option>
<option value="2" data-cost="15">2</option>
<option value="3" data-cost="30">3</option>
</select>
</p>
<p>
Total Cost: $<span id="cost">0</span>
</p>
<p><input type="submit" value="Go!"></p>
</fieldset>
</form>
jQuery:
$(function() {
$("#selectType, #selectLevel").change(function() {
var type = $("#selectType"),
level = $("#selectLevel"),
cost = $("#cost"),
typeCost = type.find(":selected").data('cost'),
levelCost = level.find(":selected").data('cost'),
total = typeCost + levelCost;
cost.html(total);
}).change(); // invoke the .change() trigger
});
See it in action here
You might want to also set something like "data-multiplier" for the level... whereas level 2 may have a 1.5x multiplier, and level 3 may have a 2x multiplier. You'd have to adjust the jQuery accordingly as well (total = typeCost * levelCostMultiplier, for example).

Answer 3

You can check if a select list has changed via jQuery's change() function.
Here's a way to do it:
HTML:
Type
<select name="type" id="type">
<option value="hotel" selected>Hotel</option>
<option value="restaurant">Restaurant</option>
<option value="casino">Casino</option>
</select>Level
<select name="level" id="level">
<option value="1" selected>1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<div id="result"></div>
jQuery:
var result = 1;
$("#type").change(function () {
var val = $(this).val();
$("#result").html("Type is " + val + ", level is " + $("#level").val());
});
$("#level").change(function () {
var val = $(this).val();
// Some basic math
result = parseInt(val) * 5;
$("#result").html("Type is " + $("#type").val() + ", level is " + val + ", result: " + result);
});
And the relevant jsfiddle:
http://jsfiddle.net/y2s4v/1/