function setOpacity(opacity_value, figure) {
 	document.getElementById(figure).style.opacity = opacity_value / 10;
 	document.getElementById(figure).style.filter = 'alpha(opacity=' + opacity_value * 50 + ')';
}

function fadePopup(figure) {
 	var opacity_value = 0;
	for( var i = 0 ; i <= 100 ; i++ ) {
		setTimeout( 'setOpacity(' + (i / 10) + ',"'+figure+'")' , 2 * i );}	
}

function swapPopup(figure_show, figure_hide) {	
 	document.getElementById(figure_hide).style.display = "none"; /* hides div figure */	
 	document.getElementById(figure_show).style.display = "block";
	document.getElementById(figure_show).style.opacity = 0;
	document.getElementById(figure_show).style.filter = "alpha(opacity = 0)";
	fadePopup(figure_show);
}

function showTxt(figure_show, link_hide) {	
	document.getElementById(link_hide).style.display = "none";
 	document.getElementById(figure_show).style.display = "block";
	document.getElementById(figure_show).style.opacity = 0;
	document.getElementById(figure_show).style.filter = "alpha(opacity = 0)";
	fadePopup(figure_show);
}

function hideTxt(figure_hide, reveal_link) {	
 	document.getElementById(figure_hide).style.display = "none";
	document.getElementById(reveal_link).style.display = "inline";
}

function highlightTxt(text_id) {	
	document.getElementById(text_id).style.background = '#f9f4c7';
}