[SOLVED] Javascript tutorial

hegerp · November 29th, 2007, 06:26 AM

Hi!

I'm very new to javascript, I'm still a fresh learner and I've got trough some tutorials and I thought I understand the language too. I thought it just until the minute I've tried to do my first piece of code.

I ask you for help, please help me if you have time. I'd like you to make me a little example tutorial or a piece of code which I can understand better. I only need a few things...

I do need a variable (myvar) which is created in the <head>. (I've done that myself and worked

The document should write this variable in some place of the <body> (document.write(myvar)) I've done that part too.
But I want it to be changeable the following way. I have some checkboxes which will represent some number (300, 390, 450). I want to create a function to be able to put an onClick event on the checkboxes so when the user checks checkboxes a certain amount would be added to the main variable.

I hope it was understandable. I hope someone will help me, and thanks for the lot beforehand!

Buh-Bye!

Rakuli · November 29th, 2007, 07:45 AM

Okay, this isn't such a daunting task to take on in your first attempt...

something like this (assuming you want the varible that is written in the body to be updated each time the checkbox is clicked)

this is very basic

HTML Code:

<html>
<head>

<!-- head stuff ect //-->
<script type="text/javascript">
var myvar = 100; // declare the varible to be used later in the piece


// this function will be called when the checkboxes are clicked, it will change the value of 
// myvar and update the area on the page
function changeMyvar (varAmount)
{

    myvar = varAmount;
    document.getElementById('myvarHolder').innerHTML = myvar;
}


</script>
</head>
<body>
<!-- this span holds the value of my var and will be uupdated later //-->
<span id="myvarHolder">
<script type="text/javascript">
document.write(myvar);
</script>
</span>


<form>
<input type="checkbox" value="300" onclick="changeMyvar(300)" />
<input type="checkbox" value="390" onclick="changeMyvar(390)" />
<input type="checkbox" value="450" onclick="changeMyvar(450)" />
</form>
</body>
</html>

The above ^^, very simply, does what you ask I believe

hegerp · November 29th, 2007, 09:31 AM

Thank you very much.

the only part I stucked in because, that was
innerHTML

Now I know it!

Thank you again!