function hide(section)
	{
	document.getElementById(section).style.display = "none" ;
	}

function show(section)
	{
	document.getElementById(section).style.display = "block" ;
	}

function visInit()
	{
	hide("main") ;
	hide("footer") ;
	}

function visToggle()
	{
	if (document.getElementById("prologue").style.display == "none")
		{
		show("prologue");
		hide("main");
		hide("footer");
		}
	else
		{
		hide("prologue");
		show("main");
		show("footer");
		}
	}