// Executa o preload das imagens, colocando a terminacao on, over, etc automaticamente
// O nome da imagem deve ser igual ao nome do objeto acrescido do sulfixo
function preload(imgSrc) {
	if (document.images) {
    imgObj = imgSrc.substring(imgSrc.lastIndexOf('/')+1,imgSrc.lastIndexOf('.'))
		eval(imgObj+' = new Image()')
		eval(imgObj+'.src = "'+imgSrc+'"')
	}
}

function changeImage(imgName,imgObj,layer) {
	if (document.images && start) {
		if (document.layers && layer) eval('document.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src')
		else document.images[imgName].src = eval(imgObj+".src")
	}
}

// Botoes
var thisButton = null
function changeImagePlus(imgName,imgObj,layer) {
	if (thisButton != imgName) {
    changeImage(imgName,imgObj,layer)
  }
}

function changeImageClick(imgName,imgObj,layer) {
  if (thisButton) changeImage(thisButton,imgName+'_out',layer)
  changeImage(imgName,imgObj,layer)
  thisButton = imgName
}