document.getElementsByClassName = function(className)
            {
                var matchingElements = new Array();
                var elements = document.getElementsByTagName('*');
                
                // For each element in the document
                for (var i = 0; i < elements.length; i++)
                {
                    // If the element has more than one class
                    if (elements[i].className.indexOf(' ') >= 0)
                    {
                        // Get classes in element
                        var classes = elements[i].className.split(' ');
                        
                        // For each class in the element
                        for(var x = 0; x < classes.length; x++)
                            if(classes[x] == className)
                                matchingElements.push(elements[x]);
                    }
                    // If the element has only one class
                    else if (elements[i].className == className)
                        matchingElements.push(elements[i]);
                }
                
                return matchingElements;
            }

	function needHack()
	{
		var pos = navigator.userAgent.indexOf("MSIE ");

		if (pos == -1)
			return false;

		var version = navigator.userAgent.substring(pos + 5);

		return (((version.indexOf("5.5") == 0) || (version.indexOf("6") == 0)) && (navigator.platform == ("Win32")));
	}
            
            window.onload = function()
            {
                var elements = document.getElementsByClassName('navigationRollover');
                // For each element in the document
                for (var i = 0; i < elements.length; i++)
                    // If the element is not the active one
                    if (!elements[i].src.match(/Active/))
                    {
                        // Add rollover effect to element
                        elements[i].onmouseover = function() { this.src = this.src.substr(0, this.src.length - 4) + 'Active.jpg'; }
                        elements[i].onmouseout = function() { this.src = this.src.replace(/Active/, ''); }
                    }

                var elements = document.getElementsByClassName('pngRollover');
                // For each element in the document
                for (var i = 0; i < elements.length; i++)
                    // If the element is not the active one
                    if (!elements[i].src.match(/Active/))
                    {
   		        if (!needHack())
			{
	                        // Add rollover effect to element
        	                elements[i].onmouseover = function() 
				{
					this.src = this.src.substr(0, this.src.length - 4) + 'Active.png';
				}
	                        elements[i].onmouseout = function()
				{
					this.src = this.src.replace(/Active/, '');
				}
			}
                    }

		// Randomise background image
		var randomNumber = Math.floor(Math.random() * 2) + 1;
		document.getElementById('Header').className += ' Background' + randomNumber;
            }