var img_width=72
var img_height=20

teaching=new Image(img_width,img_height)
teaching_on= new Image(img_width,img_height)
teaching.src="images/teaching.gif"
teaching_on.src="images/teaching_on.gif"


fellowship=new Image(img_width,img_height)
fellowship_on= new Image(img_width,img_height)
fellowship.src="images/fellowship.gif"
fellowship_on.src="images/fellowship_on.gif"

img_height=21
research=new Image(img_width,img_height)
research_on= new Image(img_width,img_height)
research.src="images/research.gif"
research_on.src="images/research_on.gif"

img_height=20
service=new Image(img_width,img_height)
service_on= new Image(img_width,img_height)
service.src="images/service.gif"
service_on.src="images/service_on.gif"

img_height=21
staff=new Image(img_width,img_height)
staff_on= new Image(img_width,img_height)
staff.src="images/staff.gif"
staff_on.src="images/staff_on.gif"

img_height=20
reference=new Image(img_width,img_height)
reference_on= new Image(img_width,img_height)
reference.src="images/reference.gif"
reference_on.src="images/reference_on.gif"

img_height=21
specials=new Image(img_width,img_height)
specials_on= new Image(img_width,img_height)
specials.src="images/specials.gif"
specials_on.src="images/specials_on.gif"

img_height=21
events=new Image(img_width,img_height)
events_on= new Image(img_width,img_height)
events.src="images/events.gif"
events_on.src="images/events_on.gif"

img_height=21
intranet=new Image(img_width,img_height)
intranet_on= new Image(img_width,img_height)
intranet.src="images/intranet.gif"
intranet_on.src="images/intranet_on.gif"

img_height=21
vacancies=new Image(img_width,img_height)
vacancies_on= new Image(img_width,img_height)
vacancies.src="images/vacancies.gif"
vacancies_on.src="images/vacancies_on.gif"

function filter(imagename,objectsrc){
	if (document.images) document.images[imagename].src=eval(objectsrc+".src")
}