function change_img(img, fn) {
		img.src = "/images/" + fn;
	}
	
	
	function show_hide(id, state) {
		document.getElementById(id).style.display = state;
	}


	function input_switch(box, io, text) {
		
		if (io == 'input') {
			if ( box.value == text ) { box.value = ""; }
		} else {
			if ( box.value == "" ) { box.value = text; }
		}
	}


	function highlight_bg(item_id, bg, img) {
		document.getElementById(item_id).style.backgroundColor = bg;
		if (img) { document.getElementById(item_id).style.backgroundImage = img; }
	}


	function highlight_text(item_id, colour) {
		document.getElementById(item_id).style.color = colour;
	}