function toggle_navbar_button (navbar_button_element, navbar_button_color, description_location_id, description_text)
{
	navbar_button_element.style.background = navbar_button_color;
	document.getElementById(description_location_id).innerHTML = ((typeof(description_text) != 'undefined') ? description_text : ' ');
}

function tin (element)
{
	element.style.cursor='hand';
}

function tout (element)
{
	element.style.background = 'red';
}