var imgHold="";

if (document.images){

AboutEnviroOn=new Image
AboutEnviroOff=new Image
CompetitionOn=new Image
CompetitionOff=new Image
StudyGuidesOn=new Image
StudyGuidesOff=new Image
PhotoTourOn=new Image
PhotoTourOff=new Image
CanonOn=new Image
CanonOff=new Image
ContactOn=new Image
ContactOff=new Image
DiscussionOn=new Image
DiscussionOff=new Image
ContributionsOn=new Image
ContributionsOff=new Image

AboutEnviroOn.src="../images/menu/AboutEnviroOn.gif"
AboutEnviroOff.src="../images/menu/AboutEnviroOff.GIF"
CompetitionOn.src="../images/menu/CompetitionOn.gif"
CompetitionOff.src="../images/menu/CompetitionOff.GIF"
StudyGuidesOn.src="../images/menu/StudyGuidesOn.gif"
StudyGuidesOff.src="../images/menu/StudyGuidesOff.GIF"
PhotoTourOn.src="../images/menu/PhotoTourOn.gif"
PhotoTourOff.src="../images/menu/PhotoTourOff.GIF"
CanonOn.src="../images/menu/CanonOn.gif"
CanonOff.src="../images/menu/CanonOff.GIF"
ContactOn.src="../images/menu/ContactOn.gif"
ContactOff.src="../images/menu/ContactOff.GIF"
DiscussionOn.src="../images/menu/DiscussionOn.gif"
DiscussionOff.src="../images/menu/DiscussionOff.GIF"
ContributionsOn.src="../images/menu/Contributions_On.gif"
ContributionsOff.src="../images/menu/Contributions_Off.gif"
}

function chgImg(imgField,newImg){

	if (imgHold!=imgField)
	{
	if (document.images){
		document[imgField].src=eval(newImg + ".src")
			
		}
	}
}