window.onload = function preloadImages() {
	
	strRoot = "http://www.makingthemostofthemersey.co.uk/"
	
	if (document.images) {
		overview_on       		= new Image();
		overview_on.src   		= strRoot + "images/overview_on.gif" ;
		overview_off     		= new Image() ;
		overview_off.src 		= strRoot + "images/overview_off.gif" ;	

		locations_on       		= new Image();
		locations_on.src   		= strRoot + "images/locations_on.gif" ;
		locations_off     		= new Image() ;
		locations_off.src 		= strRoot + "images/locations_off.gif" ;	

		activities_on       		= new Image();
		activities_on.src   		= strRoot + "images/activities_on.gif" ;
		activities_off     		= new Image() ;
		activities_off.src 		= strRoot + "images/activities_off.gif" ;	

		information_on       		= new Image();
		information_on.src   		= strRoot + "images/information_on.gif" ;
		information_off     		= new Image() ;
		information_off.src 		= strRoot + "images/information_off.gif" ;	
	}
	preloaded = true
}

function buttonon(buttonname) { 
	if ((document.images)&&(preloaded)) {
		document[ buttonname ].src = eval( buttonname + "_on.src" );
	}
}
function buttonoff(buttonname) {
	if ((document.images)&&(preloaded)) {
		document[ buttonname ].src = eval( buttonname + "_off.src" );
	}
}

function change(id, newClass) {
identity=document.getElementById(id);
identity.className=newClass;
}