source: branches/posledni/forum/styles/prosilver/template/styleswitcher.js

function fontsizeup(event)
{
        // Skip tabs; 9 being the ASCII code for a tab
        if (event && getKeyCode(event) == 9)
        {
                return true;
        }

        var active = getActiveStyleSheet();

        switch (active)
        {
                case 'A--':
                        setActiveStyleSheet('A-');
                break;

                case 'A-':
                        setActiveStyleSheet('A');
                break;

                case 'A':
                        setActiveStyleSheet('A+');
                break;

                case 'A+':
                        setActiveStyleSheet('A++');
                break;

                case 'A++':
                        setActiveStyleSheet('A');
                break;

                default:
                        setActiveStyleSheet('A');
                break;
        }

        return false;
}

function fontsizedown(event)
{
        // Skip tabs
        if (event && getKeyCode(event) == 9)
        {
                return true;
        }

        var active = getActiveStyleSheet();

        switch (active)
        {
                case 'A++' : 
                        setActiveStyleSheet('A+');
                break;

                case 'A+' : 
                        setActiveStyleSheet('A');
                break;

                case 'A' : 
                        setActiveStyleSheet('A-');
                break;

                case 'A-' : 
                        setActiveStyleSheet('A--');
                break;

                case 'A--' : 
                break;

                default :
                        setActiveStyleSheet('A--');
                break;
        }

        return false;
}

function getKeyCode(event)
{
        // IE doesn't fire the onkeypress event for tabs
        // Reference: http://www.quirksmode.org/js/keys.html

        var code = (event.keyCode) ? event.keyCode : 0;

        // Probably using FF
        if (!code && event.charCode)
        {
                code = event.charCode;
        }

        return code;
}

function setActiveStyleSheet(title)
{
        var i, a, main;

        for (i = 0; (a = document.getElementsByTagName('link')[i]); i++)
        {
                if (a.getAttribute('rel').indexOf('style') != -1 && a.getAttribute('title'))
                {
                        a.disabled = true;
                        if (a.getAttribute('title') == title)
                        {
                                a.disabled = false;
                        }
                }
        }
}

function getActiveStyleSheet()
{
        var i, a;

        for (i = 0; (a = document.getElementsByTagName('link')[i]); i++)
        {
                if (a.getAttribute('rel').indexOf('style') != -1 && a.getAttribute('title') && !a.disabled)
                {
                        return a.getAttribute('title');
                }
        }

        return null;
}

function getPreferredStyleSheet()
{
        return ('A-');
}

function createCookie(name, value, days)
{
        if (days)
        {
                var date = new Date();
                date.setTime(date.getTime() + (days*24*60*60*1000));
                var expires = '; expires=' + date.toGMTString();
        }
        else
        {
                expires = '';
        }

        document.cookie = name + '=' + value + expires + style_cookie_settings;
}

function readCookie(name)
{
        var nameEQ = name + '=';
        var ca = document.cookie.split(';');

        for (var i = 0; i < ca.length; i++)
        {
                var c = ca[i];

                while (c.charAt(0) == ' ')
                {
                        c = c.substring(1, c.length);
                }

                if (c.indexOf(nameEQ) == 0)
                {
                        return c.substring(nameEQ.length, c.length);
                }
        }

        return null;
}

function load_cookie()
{
        var cookie = readCookie('style_cookie');
        var title = cookie ? cookie : getPreferredStyleSheet();
        setActiveStyleSheet(title);
}

function unload_cookie()
{
        var title = getActiveStyleSheet();
        createCookie('style_cookie', title, 365);
}

onload_functions.push('load_cookie()');
onunload_functions.push('unload_cookie()');

/*
var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);
*/