Homework help, javascript

[DarkwingChuck]

Can anybody who knows JavaScript help me with this homework assignment?

We have to create a form for a purchase order. I have the form itself done. But we have a checkbox that when checked is supposed to put the values from the billing information fields into the shipping information fields, and set the shipping back to blanks if it's unchecked. I've tried doing it the way the teacher's slides show but nothing happens. The book doesn't even mention how to do it. I would think it'd involve onCheck but nothing happens when I use that either. So any help?

[DarkwingChuck]

Re: Homework help, javascript

Well, I managed to get the info into the fields by using onclick but that doesn't help with getting it cleared back out. I can't get OnCheck or OnUncheck to do anything no matter what I do.

[Wavelength]

Re: Homework help, javascript

I haven't worked with JavaScript forever, so I don't know whether this will apply, but in the Visual Studio programming environments we use something like:

(in C#) if (CheckBox1.Checked == true)
{
(code)
}

(in Visual Basic) If (CheckBox1.Checked = True)
(code)
End If

Of course you can also use False. I suppose you could put this under a "Changed" or "Checked" event handler, but if you're using a button to run an event, let's say to fill in the fields or calculate something, that would be the ideal place to put the "If the checkbox is checked then" code.

[DarkwingChuck]

Re: Homework help, javascript

We're doing the javascript in plain HTML pages so I don't think I could've used C or Visual Basic code but I ended up doing basically that as a function activated by onclick. I don't think that's how we were supposed to do it but it works.

[Alzar]

Re: Homework help, javascript

Yeah..If oncheck doesn't do anything, initiate a function onclick and then check if the thing is checked in that function in an if statement.

That sounds like what you did, so, WOO.

You'll find with internets code, particularly javascript & css, that different browsers act differently with the same code. It blows.

[thetruecoolness]

Re: Homework help, javascript

Well if I would have had internet I probably could have answered this.

You could probably use onchange instead. Or the other option is to use onclick and use this function.

onclick = "if (this.checked) { // do stuff } else { // do other thing }"

This way you make sure that they actually checked it.

For future reference three very good resource for this are

www.javascriptkit.com
www.quirksmode.com
www.alistapart.com

But yeah writing cross-browser Javascript is a pain in the ass, especially with events. My chat does a lot of this.

EDIT (slight correction in wording) :
And FYI oncheck is not an attribute. Also all attribute names are lower case since well in XHTML, which is what everything will be soon.

[DarkwingChuck]

Re: Homework help, javascript

And FYI oncheck is not a function. Also all function names are lower case since they are XHTML attributes.

Dang that teacher and his confusing powerpoint slides.

[thetruecoolness]

Re: Homework help, javascript

Dang that teacher and his confusing powerpoint slides.

Well you teacher might be correct for IE or something, but it's not a cross browser attribute. Which means if you really want a lot of people to use you're site it's useless.

And you people and your .NET, real coders make their code from scratch .

[Chad]

Re: Homework help, javascript

But... but... Intellisense is so awesome.

[thetruecoolness]

Re: Homework help, javascript

Well yeah, but lots of other editors have autocomplete as well (Eclipse). Just they don't write the HTML for you behind the scenes using all this overly Object Oriented stuff. But yeah ASP.NET is pretty nice, I just really don't like things that do too much for you, as when you want to do something really customized or complex, it's usually more a hindrance than a help.