if (document.images){
	introduction_off=new Image
	introduction_on=new Image
	search_off=new Image
	search_on=new Image
	regsearch_on=new Image
	regsearch_off=new Image
	advsearch_on=new Image
	advsearch_off=new Image
	browse_off=new Image
	browse_on=new Image
	browsegen_on=new Image
	browsegen_off=new Image
	browsesub_on=new Image
	browsesub_off=new Image
	resources_off=new Image
	resources_on=new Image
	about_off=new Image
	about_on=new Image
	bibliography_on=new Image
	bibliography_off=new Image
	links_on=new Image
	links_off=new Image
	acknowledgments_on=new Image
	acknowledgments_off=new Image
	institutions_on=new Image
	institutions_off=new Image
	reproductions_on=new Image
	reproductions_off=new Image
	technical_on=new Image
	technical_off=new Image
		
	introduction_off.src="images/introduction_off.gif"
	introduction_on.src="images/introduction_on.gif"
	search_off.src="images/search_off.gif"
	search_on.src="images/search_on.gif"
	regsearch_on.src="images/regsearch_on.jpg"
	regsearch_off.src="images/regsearch_off.jpg"
	advsearch_on.src="images/advsearch_on.jpg"
	advsearch_off.src="images/advsearch_off.jpg"
	browse_off.src="images/browse_off.gif"
	browse_on.src="images/browse_on.gif"
	browsegen_on.src="images/browsegen_on.jpg"
	browsegen_off.src="images/browsegen_off.jpg"
	browsesub_on.src="images/browsesub_on.jpg"
	browsesub_off.src="images/browsesub_off.jpg"
	resources_off.src="images/resources_off.gif"
	resources_on.src="images/resources_on.gif"
	about_off.src="images/about_off.gif"
	about_on.src="images/about_on.gif"
	bibliography_on.src="images/bibliography_on.jpg"
	bibliography_off.src="images/bibliography_off.jpg"
	links_on.src="images/links_on.jpg"
	links_off.src="images/links_off.jpg"
	acknowledgments_on.src="images/acknowledgments_on.jpg"
	acknowledgments_off.src="images/acknowledgments_off.jpg"
	institutions_on.src="images/institutions_on.jpg"
	institutions_off.src="images/institutions_off.jpg"
	reproductions_on.src="images/reproductions_on.jpg"
	reproductions_off.src="images/reproductions_off.jpg"
	technical_on.src="images/technical_on.jpg"
	technical_off.src="images/technical_off.jpg"
}

function chgImg(imgField,newImg){
	if (document.images){
		document[imgField].src=eval(newImg+".src")
	}
	
}