Refresh my memory

Anon

Hi, what I need to do is have some info on the page change automatically when a user make a selection based on two fields.

ie you go to a site and want to order some eggs so from the dropdown menu you choose eggs and in the second one you choose the number of eggs you want the price would then change to reflect the new price without you needing to refresh the page.

How would i do this in PHP and does anybody have some code that i could use to do this - no need to re-invent the wheel.

Thnx in advance,
Charlie

linus

If you want to have something change without refreshing the page, that would have to be done in JavaScript, not PHP. PHP can only execute code in response to an HTTP request, but JavaScript (which is CLIENT SIDE) can execute code based on use action, and it doesn't have to be all at the same time.

If this is what you want, it should be relatively easy.

Anon

Know where I can find the code, or someone to help write it?

Anon

Sorry, forgot to say thank you for helping me this far!

linus

No problem. I wrote this little JavaScript for the heck of it. If you view source you should be able to figure it out, it's pretty well commented. If you have any questions, I'll still be here.

http://www.nvolt.com/price_calc.html

Anon

is there any way to make it do it on a 'losefocus' or 'onchange' simular to the events procedures in MS Access, I know ASP can do this and figured PHP would be able to also - but JS is fine, thnx.

but if it could update without the need of clicking the button that would be PERFECT!

Thnx again!

Anon

Also how would I be able to add a discount system to this.

say for example you subscribe for a magazine and if you pay monthly its $9.95/mo but if you pay yearly its only $99.50/yr and you get two months free.

This also will help me out greatly.

Thnx for the script too Linus!

Regs,
Charlie

linus

Yes: use the onchange event of the text field and the select box to trigger the calculation. Example:

linus

Well, you could have a function to determine the price of an item. It would do all the work to see the amount being purchased, and discount accordingly. Like so;

function findPrice(amount, item) {

// What we multiply by to discount
var factor;

// 10 or over - discount to 80%
if (amount >= 10) {
factor = 0.8;

// 5 or over - discount to 90%
} else if (amount >= 5) {
factor = 0.9;

// Under 5 - normal price
} else {
factor = 1;
}

// Return price
return prices[item] amount factor;
}

Anon

ok what i have done wilst i try to get the code right is make two drop down menus, one for the magazine they want and another for the term they wish to pay for.

in my example they have 4 possible magazines to pick from and 3 possible payment terms these being monthly, bi-annyal, or annual.

But it is not working for me.

how do i get it to take the valuse for each

please take a look at the URL below to see a --not so well-- working example:
http://www.delta-strike.com/mag_example.htm

Regards,
Charlie

linus

This is line 48 of your source code:

return Mag_prices[item] * term_prices[item];

The variable item is not defined. See these lines, right above that one?

	var Mag_field	= document.getElementById('Mag_field');
	var Mag			= Mag_field.options[Mag_field.selectedIndex].value;
	var term_field	= document.getElementById('term_field');
	var term		= term_field.options[term_field.selectedIndex].value;

The purpose of these lines is to get the magazine and the term that the user selected. The variables you should be using on line 48 are Mag and term, like this:

return Mag_prices[Mag] * term_prices[term];

I think that will work.