var base_fontsize = 75;
var min_fontsize = 75;
var fontsize_cookiename = 'canteen_FONTSIZE';



function fontsize_init()
{
	new_size = GetCookie(fontsize_cookiename);
	if (new_size > min_fontsize)
	{
		document.getElementsByTagName('body')[0].style.fontSize = new_size + '%';
		base_fontsize = new_size;
	}
}

function fontsize_up()
{
	// wenn ich einen + verwende, wird es manchmal als Konkatenation interpretiert. Aber nicht immer.
	// Mit einem minus gehts scheinbar immer.
	// HACK!!!
	new_size = base_fontsize - (-10);
	document.getElementsByTagName('body')[0].style.fontSize = new_size + '%';
	base_fontsize = new_size;
	SetCookie(fontsize_cookiename, new_size);
	
}

function fontsize_down()
{
	new_size = base_fontsize - 10;
	if (new_size < min_fontsize)
	{
		new_size = min_fontsize;
	}
	document.getElementsByTagName('body')[0].style.fontSize = new_size + '%';
	base_fontsize = new_size;
	SetCookie(fontsize_cookiename, new_size);
}
function SetCookie(cookieName,cookieValue,nDays) {
    var today = new Date();
    var expire = new Date();
    if (nDays==null || nDays==0) nDays=3650;
    expire.setTime(today.getTime() + 3600000*24*nDays);
    document.cookie = cookieName+"="+escape(cookieValue)+ ";path=/;expires="+expire.toGMTString();
}

function DelCookie(cookieName) {
    var today = new Date();
    var expire = new Date();
    expire.setTime(today.getTime() - 1);
    document.cookie = cookieName+"="+escape('')+ ";expires="+expire.toGMTString();
}

function GetCookie( 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;
	}
}