// pre-load roll-over images here

// construct new images

sub_about_off = new Image
sub_about_on = new Image
sub_lessons_off = new Image
sub_lessons_on = new Image
sub_clinics_off = new Image
sub_clinics_on = new Image
sub_train_off = new Image
sub_train_on = new Image
sub_tech_off = new Image
sub_tech_on = new Image

// define src attributes

sub_about_off.src = "../banner/sub_about_off.gif"
sub_about_on.src = "../banner/sub_about_on.gif"
sub_lessons_off.src = "../banner/sub_lessons_off.gif"
sub_lessons_on.src = "../banner/sub_lessons_on.gif"
sub_clinics_off.src = "../banner/sub_clinics_off.gif"
sub_clinics_on.src = "../banner/sub_clinics_on.gif"
sub_train_off.src = "../banner/sub_train_off.gif"
sub_train_on.src = "../banner/sub_train_on.gif"
sub_tech_off.src = "../banner/sub_tech_off.gif"
sub_tech_on.src = "../banner/sub_tech_on.gif"

// here is the rollover function

	// this function switches to a new image in the specified field
	function changeImg(imgField, newImg) {
		if (document.images) {
			document[imgField].src =
				eval(newImg + ".src")
		}
	}