function preloadImages() {
if (document.images)
	{
	var btn_strategies_roll = new Image
		btn_strategies_roll.src = "../../images/btn_strategies_over.gif"
	var btn_tellafriend_roll = new Image
		btn_tellafriend_roll.src = "../../images/btn_tellafriend_over.gif"
	var btn_downloads_roll = new Image
		btn_downloads_roll.src = "../../images/btn_downloads_over.gif"
	var btn_getthevideo_roll = new Image
		btn_getthevideo_roll.src = "../../images/btn_getthevideo_over.gif"
	var btn_standards_roll = new Image
		btn_standards_roll.src = "../../images/btn_standards_over.gif"
	var btn_discussionforum_roll = new Image
		btn_discussionforum_roll.src = "../../images/btn_discussionforum_over.gif"
	var btn_designclassroom_roll = new Image
		btn_designclassroom_roll.src = "../../images/btn_designclassroom_over.gif"
	var btn_visualizing_roll = new Image
		btn_visualizing_roll.src = "../../images/btn_visualizing_over.gif"
	var btn_priorknowledge_roll = new Image
		btn_priorknowledge_roll.src = "../../images/btn_priorknowledge_over.gif"
	var btn_makingconnections_roll = new Image
		btn_makingconnections_roll.src = "../../images/btn_makingconnections_over.gif"
	var btn_questioning_roll = new Image
		btn_questioning_roll.src = "../../images/btn_questioning_over.gif"
	var btn_inferring_roll = new Image
		btn_inferring_roll.src = "../../images/btn_inferring_over.gif"
	var btn_summarizing_roll = new Image
		btn_summarizing_roll.src = "../../images/btn_summarizing_over.gif"
	var btn_evaluating_roll = new Image
		btn_evaluating_roll.src = "../../images/btn_evaluating_over.gif"
	var btn_synthesizing_roll = new Image
		btn_synthesizing_roll.src = "../../images/btn_synthesizing_over.gif"
	var btn_usingstrategies_roll = new Image
		btn_usingstrategies_roll.src = "../../images/btn_usingstrategies_over.gif"
	var btn_studentarea_roll = new Image
		btn_studentarea_roll.src = "../../images/btn_studentarea_over.gif"
	var btn_teacherarea_roll = new Image
		btn_teacherarea_roll.src = "../../images/btn_teacherarea_over.gif"
	var btn_aboutproject_roll = new Image
		btn_aboutproject_roll.src = "../../images/btn_aboutproject_over.gif"
	var btn_credits_roll = new Image
		btn_credits_roll.src = "../../images/btn_credits_over.gif"
	var btn_bibliography_roll = new Image
		btn_bibliography_roll.src = "../../images/btn_bibliography_over.gif"
	var btn_vis_si_roll = new Image
		btn_vis_si_roll.src = "../../images/btn_vis_si_over.gif"
	var btn_vis_sv_roll = new Image
		btn_vis_sv_roll.src = "../../images/btn_vis_sv_over.gif"
	var btn_vis_tv_roll = new Image
		btn_vis_tv_roll.src = "../../images/btn_vis_tv_over.gif"
	var btn_vis_lessons_roll = new Image
		btn_vis_lessons_roll.src = "../../images/btn_vis_lessons_over.gif"
	var btn_vis_tt_roll = new Image
		btn_vis_tt_roll.src = "../../images/btn_vis_tt_over.gif"
	var btn_vis_books_roll = new Image
		btn_vis_books_roll.src = "../../images/btn_vis_books_over.gif"
	var btn_vis_research_roll = new Image
		btn_vis_research_roll.src = "../../images/btn_vis_research_over.gif"
	var btn_vis_links_roll = new Image
		btn_vis_links_roll.src = "../../images/btn_vis_links_over.gif"
	var btn_vis_downloads_roll = new Image
		btn_vis_downloads_roll.src = "../../images/btn_vis_downloads_over.gif"
	var btn_next_roll = new Image
		btn_next_roll.src = "../../images/btn_next_over.gif"
	var btn_back_roll = new Image
		btn_back_roll.src = "../../images/btn_back_over.gif"
	}
}