var but1n = new Image()
but1n.src = "images/but_visitor_on.gif"
var but1a = new Image()
but1a.src = "images/but_visitor_off.gif"
var but2n = new Image()
but2n.src = "images/but_community_on.gif"
var but2a = new Image()
but2a.src = "images/but_community_off.gif"
var but3n = new Image()
but3n.src = "images/but_business_on.gif"
var but3a = new Image()
but3a.src = "images/but_business_off.gif"
var but4n = new Image()
but4n.src = "images/but_cevents_on.gif"
var but4a = new Image()
but4a.src = "images/but_cevents_off.gif"
var but5n = new Image()
but5n.src = "images/but_about_on.gif"
var but5a = new Image()
but5a.src = "images/but_about_off.gif"

function act(imgName) {

document[imgName].src = eval(imgName + 'n.src')
}

function inact(imgName) {

document[imgName].src = eval(imgName + 'a.src')
}