// JavaScript Document

/* preload the images required for the menu tabs */

if (document.images) {
	about = new Image
	about_over = new Image
	curriculum = new Image
	curriculum_over = new Image
	units = new Image
	units_over = new Image
	activities = new Image
	activities_over = new Image
	lessons = new Image
	lessons_over = new Image
	
	about.src = "images/homemenu/tab_about.png"
	about_over.src = "images/homemenu/tab_about_over.png"
	curriculum.src = "images/homemenu/tab_curriculum.png"
	curriculum_over.src = "images/homemenu/tab_curriculum_over.png"
	units.src = "images/homemenu/tab_units.png"
	units_over.src = "images/homemenu/tab_units_over.png"
	activities.src = "images/homemenu/tab_activities.png"
	activities_over.src = "images/homemenu/tab_activities_over.png"
	lessons.src = "images/homemenu/tab_lessons.png"
	lessons_over.src = "images/homemenu/tab_lessons_over.png"	
}

/* function to show the right menu tab highlighted when mouse is over */

function highlightTab(menuTab) {	
	tabtohighlight = document.getElementById(menuTab)
	tabtohighlight.src = eval(menuTab + '_over.src')
}

/* function to put the original menu tab back in when mouse moves off */

function menuRevert(menuTab) {
	tabtoreset = document.getElementById(menuTab)
	tabtoreset.src = eval(menuTab + '.src')
}