// preload navigation images and their mouseovers
function init()
{
    if ( document.getElementById )
    	var x = document.getElementById( 'navigation' ).getElementsByTagName( 'IMG' );
    else if ( document.all )
    	var x = document.all[ 'navigation' ].all.tags( 'IMG' );
    else return;
    
    var preloads = new Object();
    var imageId;

    for ( var i = 0; i < x.length; i++ )
	{
	    // check if the image has id - if it doesn't then it is not a navigation item
	    // also check if the image contains 'over' text - if it does then this is 
	    // the mouseover image of the current page and it should not be preloaded
	    if( x[ i ].id == '' || x[ i ].src.match( 'over' ) != null )
	        continue;
	        
	    imageId = x [ i ].id.replace('ctl00_cphUpperMenu_upperMenu_navigation', '');
	    if(imageId == 'Left' || imageId == 'Right')
	        continue;
	    preloads[ 'n' + x[ i ].id ] = new Image;
		preloads[ 'n' + x[ i ].id ].src = 'Images/navigation_'+ imageId+ '.gif';
		preloads[ 'o' + x[ i ].id ] = new Image;
		preloads[ 'o' + x[ i ].id ].src = 'Images/navigation_'+ imageId + '_over.gif';
		x[ i ].onmouseover = function () { this.src = preloads[ 'o' + this.id ].src; }
		x[ i ].onmouseout = function () { this.src = preloads[ 'n' + this.id ].src; }
	}
}