var visit = null
var numImages = null

if (!(visit = GetCookie ("HomeImage"))) 
{
	visit = 1
	SetCookie ('HomeImage', visit, expdate, '/', null, false)
}

else
{
	numImages = 13
	visit = GetCookie ('HomeImage')

	visit++
	if (visit > numImages) visit = 1
	SetCookie ('HomeImage', visit, expdate, '/', null, false)
}