Javascript image swap on rollover.

[rickya100]

Hi and thanks for looking.

The problem i'm having is simply getting an image to swap on a mouseover. Well I sort of had it working but then I cahnged the function to try and accomodate for more images and it just fell over dead.

Let me show you the function I have for it. Bear in mind I'm used to coding but more PHP and VB rather than JavaScript so the code ain't going to be pretty, sorry.

<script language="javascript1.5">
Rollimage = new Array()
   
Rollimage[0] = new Image(244,244) 
Rollimage[0].src = "images/personal_up.png" 
Rollimage[1] = new Image(244,244)
Rollimage[1].src = "images/personal_over.png"

Rollimage[2] = new Image(244,244) 
Rollimage[2].src = "images/thoughts_up.png" 
Rollimage[3] = new Image(244,244)
Rollimage[3].src = "images/thoughts_over.png"

Rollimage[4] = new Image(244,244) 
Rollimage[4].src = "images/work_up.png" 
Rollimage[5] = new Image(244,244)
Rollimage[5].src = "images/work_over.png"

function SwapBack(image, number){
  document.[image].src = Rollimage[number].src;
  return true;
}
function SwapOut(image, number) {
  document.[image].src = Rollimage[number].src;
  return true;
} 

</script>

Thats my function which i have placed in a PHP file which I then include on everypage.
Now the 3 image links that I am calling the function from.

<div class="icons">
<a href="#" onmouseover="SwapOut(personal, 0)" onmouseout="SwapBack(personal, 1)"><img name="personal" alt="logo" src="images/personal_up.png" /></a>
<a href="#" onmouseover="SwapOut(thoughts, 2)" onmouseout="SwapBack(thoughts, 3)"><img name="thoughts" alt="logo" src="images/thoughts_up.png" /></a>
<a href="#" onmouseover="SwapOut(work, 4)" onmouseout="SwapBack(work, 5)"><img name="work" alt="logo" src="images/work_up.png" /></a>
</div>

So that's it. As i say I had it working with only one image but trying to expand upon the example i found hasn't worked.

Any tips or help that you could post would be great.

Thanks for looking.

BTW I have searched google and read many articles on this but still can't get it to work. Also I have searched previous articles on DaniWeb and again none solve the problem.

The address of the page is www.richardjohnashe.com/portfolio.

[HenryGR]

At a first glance, I can see that on your calling code:

<div class="icons"> <a href="#" onmouseover="SwapOut(personal, 0)" onmouseout="SwapBack(personal, 1)"><img name="personal" alt="logo" src="images/personal_up.png" /></a>.... </div>

you are referencing undefined variables. Have you tried to replace the call for:

onmouseover="SwapOut(personal, 0)"

with

onmouseover="SwapOut('personal', 0)"

as I guess you want to address the object with name 'personal' instead the object contained in personal variable.

Hope this helps.

[AaronASterling]

Also you seem to be relying on the javascript semi-colon insertion "feature". the language does require semi-colons at the end of every statement. It's just that it will supply them for you if you omit them. This can cause bugs when it gets it wrong. they can be very hard bugs to figure out. Don't rely on it and supply all semicolons yourself. And also you might want to consider using Rollimage = []; instead of Rollimage=new Array(); . This is (i believe) faster. Because Array is a built in class, you do not need to call its constructor.

[rickya100]

HenryGR and AaronASterling, thanks both for the advice, unfortunately it still doesn't work when I enclose the variables in quotation marks, when I add a semi colon to the end of lines or when I replace the 'new array' text with just the square brackets [].

If there is anything else you think is posibly wrong, however small it would be great if you could post it.

And i assume that in the code I don't have to actually explicitly create the variables 'image' and 'number'. Or do I?

[AaronASterling]

Sorry mate, my earlier comments would have nothing to do with why your script fails. I was just pointing out general coding style. never rely on semi-colen insertion. as to your problem...

in your event handlers try document[image].src instead of document.[image].src i haven't actually tried it but at least the syntax is correct

[rickya100]

AaronASterling u got it!

GREAT!!!

Removing the .from between the document and square brackets got it. I also had to swap my numbers that I'm passing around bit to get the right order of swaps but you got it.

Man thanks very much for the time you spent. Fantastic. O and also thanks to henryGR as well, thanks man.

[Geoff Hinde]

Hi!

Have read your thread and tried everything. But still can't make it work.

I can get the first image up but not the second or the mouseOver.

My code is:

<script language="javascript1.5">
	Rollimage = Rollimage = [];
	&nbsp;
	Rollimage[0] = new Image(200,150) 
	Rollimage[0].src = "automotive/images/mustangbefore.jpg" 
	Rollimage[1] = new Image(200,150)
	Rollimage[1].src = "automotive/images/mustangafter.jpg"
	&nbsp;
	function SwapBack(image, number){
	document[image].src = Rollimage[number].src;
	return true;
	}
	function SwapOut(image, number) {
	document[image].src = Rollimage[number].src;
	return true;
	} 
	
	</script>
//-->
</script>
</head>
<body bgcolor="#FFFFFF" alink="#008000" vlink="#800080" link="#0000FF" text="#000000" onload="preloadImages()"><p>

 <p>


<a href="#" onmouseover="SwapOut('mustangafter', 0)" onmouseout="SwapBack(mustangbefore)"><img name="mustang" alt="Mustang" src="images/mustangbefore.jpg" /></a>
</body>
</html>

The page is at www.sodablast.net.au/automotive/test.html

The images are in the automotive sub-directory at #images.

Apologies for being a nuisance, but I can't make it work.

Looks like a good script.

Any help appreciated.

Gift in mail from Down Under (Australia) in appreciation if you can help me out.

regards

Geoff A Hinde

[HenryGR]

Hi!

Have read your thread and tried everything. But still can't make it work.

I can get the first image up but not the second or the mouseOver.

My code is:

<script language="javascript1.5">
	Rollimage = Rollimage = [];
	&nbsp;
	Rollimage[0] = new Image(200,150) 
	Rollimage[0].src = "automotive/images/mustangbefore.jpg" 
	Rollimage[1] = new Image(200,150)
	Rollimage[1].src = "automotive/images/mustangafter.jpg"
	&nbsp;
	function SwapBack(image, number){
	document[image].src = Rollimage[number].src;
	return true;
	}
	function SwapOut(image, number) {
	document[image].src = Rollimage[number].src;
	return true;
	} 
	
	</script>
//-->
</script>
</head>
<body bgcolor="#FFFFFF" alink="#008000" vlink="#800080" link="#0000FF" text="#000000" onload="preloadImages()"><p>

 <p>


<a href="#" onmouseover="SwapOut('mustangafter', 0)" onmouseout="SwapBack(mustangbefore)"><img name="mustang" alt="Mustang" src="images/mustangbefore.jpg" /></a>
</body>
</html>

The page is at www.sodablast.net.au/automotive/test.html

The images are in the automotive sub-directory at #images.

Apologies for being a nuisance, but I can't make it work.

Looks like a good script.

Any help appreciated.

Gift in mail from Down Under (Australia) in appreciation if you can help me out.

regards

Geoff A Hinde

Some lines within your code call my attention:
Rollimage = Rollimage = [];
should be:
Rollimage = new Array();
then the two lines with " " are meaningless, please remove them.
The two functions (SwapOut and SwapBack) are exactly he same code... Why to have them dplicated instead of use just one of them?

Also, you are using only one image in your document, with the name attribute of 'mustang', but you are trying to find images with the names of "mustangbefore" and "mustangafter".

The call to any of the functions that you have, should be something like:
onmouseover="SwapOut('mustang', 0)"
where 'mustang' is the name of the image (within the HTML document body) that you want to alter, and 0 is the number of the matrix index that you want to place in.

Within the functions that you have, you attempt to address the image using:
document[image].src = Rollimage[number].src;
and, in order to properly address the image that you want to change, the line should be:
document.getElementById(image).src = Rollimage[number].src;

[Geoff Hinde]

Henry - thanks.

Have followed your advice so far but still does not seem to work.

Code now is:

<script language="javascript1.5">
    Rollimage = new Array();
    Rollimage[0] = new Image(200,150)
    Rollimage[0].src = "automotive/images/mustangbefore.jpg"
    Rollimage[1] = new Image(200,150)
    Rollimage[1].src = "automotive/images/mustangafter.jpg"
    function SwapOut(image, number) {
    document.getElementById(image).src = Rollimage[number].src;
    return true;
    }   
</script>

And call is

<a href="#" onmouseover="SwapOut('mustangafter.jpg', 1)" onmouseout="SwapOut('mustangbefore.jpg', 0)"><img name="mustang" src="images/mustangbefore.jpg" /></a>

Test page updated.

Would greatly appreciate it if you could tweak this for me.

Much thanks

Geoff

[HenryGR]

Geoff,
please alter your call to:

<a href="#" onmouseover="SwapOut('mustang', 1)" onmouseout="SwapOut('mustang', 0)"><img name="mustang" src="images/mustangbefore.jpg" /></a>

Rgds.