var defaultsize = 12;
var minsize = 6;
var maxsize = 24;
var fontunit = 'pt';
var divid = 'content';

var taglist = new Array("P","H2","LI");
var inclist = new Array(0, 2, -2);

var pclasslist = new Array();
pclasslist["poem"] = 0;
pclasslist["author"] = -2;
pclasslist["epigraph"] = -2;
pclasslist["previous"] = -2;
pclasslist["footnote"] = -2;

var myfontsize = getFontSize();
		
window.onload = function() {
	if (Get_Cookie('fontsize') != null) {
		setFontSize();
		saveFontSize();
	}
} 

function getFontSize(){
	var currentsize = parseInt(Get_Cookie('fontsize'));
	if (isNaN(currentsize) || currentsize < minsize || currentsize > maxsize)
		currentsize = defaultsize;
	return currentsize;
}

function setFontSize() {
	if (document.getElementById) {
		var mydiv = document.getElementById(divid);
		if (mydiv && mydiv.getElementsByTagName) {
			for (var i = 0; i < taglist.length; i++) {
				var children = mydiv.getElementsByTagName(taglist[i]);
				if (children) {
					for (var j = 0; j < children.length; j++) {
						var c = children[j];
						var newsize = myfontsize + inclist[i];
						if (taglist[i] == 'P' && c.className && pclasslist[c.className]) {
							newsize += pclasslist[c.className];
						}
						c.style.fontSize = '' + newsize + fontunit;						
					}
				}
			}			
		}
	}
}	

function increaseFontSize() {
	if (myfontsize < maxsize)
		myfontsize++;
	setFontSize();
	saveFontSize();
}

function decreaseFontSize() {
	if (myfontsize > minsize) 
		myfontsize--;
	setFontSize();
	saveFontSize();
}

function resetFontSize() {
	myfontsize = defaultsize;
	setFontSize();
	Delete_Cookie('fontsize');
}

function saveFontSize() {
	Set_Cookie('fontsize', ''+myfontsize);
}
	


/*
	http://techpatterns.com/downloads/javascript_cookies.php
*/

function Set_Cookie( name, value, expires, path, domain, secure ) 
{
	
	// set time, it's in milliseconds
	var today = new Date();
	today.setTime( today.getTime() );
	
	/*
	if the expires variable is set, make the correct
	expires time, the current script below will set
	it for x number of days, to make it for hours,
	delete * 24, for minutes, delete * 60 * 24
	*/
	if ( expires )
	{
	expires = expires * 1000 * 60 * 60 * 24;
	}
	var expires_date = new Date( today.getTime() + (expires) );
	
	document.cookie = name + "=" +escape( value ) +
	( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) +
	( ( path ) ? ";path=" + path : "" ) +
	( ( domain ) ? ";domain=" + domain : "" ) +
	( ( secure ) ? ";secure" : "" );
}

function Get_Cookie( check_name ) 
{
	// first we'll split this cookie up into name/value pairs
	// note: document.cookie only returns name=value, not the other components
	var a_all_cookies = document.cookie.split( ';' );
	var a_temp_cookie = '';
	var cookie_name = '';
	var cookie_value = '';
	var b_cookie_found = false; // set boolean t/f default f

	for ( i = 0; i < a_all_cookies.length; i++ )
	{
		// now we'll split apart each name=value pair
		a_temp_cookie = a_all_cookies[i].split( '=' );


		// and trim left/right whitespace while we're at it
		cookie_name = a_temp_cookie[0].replace(/^\s+|\s+$/g, '');

		// if the extracted name matches passed check_name
		if ( cookie_name == check_name )
		{
			b_cookie_found = true;
			// we need to handle case where cookie has no value but exists (no = sign, that is):
			if ( a_temp_cookie.length > 1 )
			{
				cookie_value = unescape( a_temp_cookie[1].replace(/^\s+|\s+$/g, '') );
			}
			// note that in cases where cookie is initialized but no value, null is returned
			return cookie_value;
			break;
		}
		a_temp_cookie = null;
		cookie_name = '';
	}
	if ( !b_cookie_found )
	{
		return null;
	}
}

function Delete_Cookie( name, path, domain ) {
	if ( Get_Cookie( name ) ) 
		document.cookie = name + "=" +
	( ( path ) ? ";path=" + path : "") +
	( ( domain ) ? ";domain=" + domain : "" ) +
	";expires=Thu, 01-Jan-1970 00:00:01 GMT";
}