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';
}

function isChecked() {
if (document.sample_form.samples.checked == true) { 
	 displaySamples();
	} else {
		displayAll(); 
		}
}

var noSample = new Array();

noSample[0] = "no_sample_2001";
noSample[1] = "no_sample_2001b";
noSample[2] = "no_sample_2001c";

noSample[3] = "no_sample_1991";
noSample[4] = "no_sample_1991b";
noSample[5] = "no_sample_1991c";

noSample[6] = "no_sample_1981";
noSample[7] = "no_sample_1981b";
noSample[8] = "no_sample_1981c";

noSample[9] = "no_sample_1971";
noSample[10] = "no_sample_1971b";

noSample[11] = "no_sample_1961";
noSample[12] = "no_sample_1961b";
noSample[13] = "no_sample_1961c";

noSample[14] = "no_sample_1951";
noSample[15] = "no_sample_1951b";
noSample[16] = "no_sample_1951c";

noSample[17] = "no_sample_1941";
noSample[18] = "no_sample_1941b";

noSample[19] = "no_sample_1931";
noSample[20] = "no_sample_1931b";
noSample[21] = "no_sample_1931c";

noSample[22] = "no_sample_1921";
noSample[23] = "no_sample_1921b";
noSample[24] = "no_sample_1921c";
noSample[25] = "no_sample_1921d";

noSample[26] = "no_sample_1914";
noSample[27] = "no_sample_1914b";
noSample[28] = "no_sample_1914c";



function displaySamples() {	
	for (i = 0; i < noSample.length; i++){
		document.getElementById(noSample[i]).style.display = "none";
	}
	
}

function displayAll() {
	for (i = 0; i < noSample.length; i++){
	document.getElementById(noSample[i]).style.display = "block";
	}

}