// RIL1.0 :: Random image link
// ***********************************************
// DOM scripting by brothercake -- http://www.brothercake.com/
// Original concept by Andy Clarke -- http://www.stuffandnonsense.co.uk/
// Create element and attributes based on a method by beetle -- http://www.peterbailey.net/
//************************************************
//open initialisation function
function randomImageLink() { 
//************************************************



/*****************************************************************************
 Define image links
*****************************************************************************/


//identify an image link ('link-id')
var button = new imageLink('udm-button');

//add possibilities ('href', 'title text', 'src', 'width', 'height', 'alt text')
button.addLink('http://www.udm4.com/', 'Default page', '/scripts/imagelink/buttons/udm4-button88x31.gif', '88', '31', 'Accessible Website Menu [default]');
button.addLink('http://www.udm4.com/?page=green', 'Green page', '/scripts/imagelink/buttons/udm4-greenbutton88x31.gif', '88', '31', 'Accessible Website Menu [green]');
button.addLink('http://www.udm4.com/?page=red', 'Red page', '/scripts/imagelink/buttons/udm4-redbutton88x31.gif', '88', '31', 'Accessible Website Menu [red]');
button.addLink('http://www.udm4.com/?page=purple', 'Purple page', '/scripts/imagelink/buttons/udm4-purplebutton88x31.gif', '88', '31', 'Accessible Website Menu [purple]');
button.addLink('http://www.udm4.com/?page=blue', 'Blue page', '/scripts/imagelink/buttons/udm4-bluebutton88x31.gif', '88', '31', 'Accessible Website Menu [blue]');
button.addLink('http://www.udm4.com/?page=black', 'Black page', '/scripts/imagelink/buttons/udm4-blackbutton88x31.gif', '88', '31', 'Accessible Website Menu [black]');
button.addLink('http://www.udm4.com/?page=white', 'White page', '/scripts/imagelink/buttons/udm4-whitebutton88x31.gif', '88', '31', 'Accessible Website Menu [white]');

//select a possibility at random
button.selectLink();


/*****************************************************************************
*****************************************************************************/



//close initialisation function
};




//image link constructor
function imageLink(linkid)
{
	//set link object
	this.link = document.getElementById(linkid);
	
	//create an empty array of possible links
	this.possibles = [];
};


//add a possibility 
imageLink.prototype.addLink = function()
{
	//store arguments in possible links array
	this.possibles[this.possibles.length] = arguments;
};


//select a possibility at random 
imageLink.prototype.selectLink = function()
{
	//if the link exists
	if(this.link != null)
	{
		//get a random item from the array
		this.rnd = this.possibles[Math.floor(Math.random() * this.possibles.length)];
		
		//set new link attributes 
		this.link.href = this.rnd[0];
		this.link.title = this.rnd[1];
		
		//get image object inside it
		this.img = this.link.getElementsByTagName('img')[0];
		
		//if it exists
		if(this.img != null)
		{
			//set new image attributes
			this.img.src = this.rnd[2]; 
			this.img.width = this.rnd[3]; 
			this.img.height = this.rnd[4]; 
			this.img.alt = this.rnd[5]; 
		}
	}
};


//call initialisation function if supported
if(typeof document.getElementById != 'undefined') { randomImageLink(); }