var fontsize = 'small'

function get_cookie(c_name) {
    if (document.cookie.length>0) {
        c_start=document.cookie.indexOf(c_name + "=");
        if (c_start!=-1) {
            c_start=c_start + c_name.length+1;
            c_end=document.cookie.indexOf(";",c_start);
            if (c_end==-1) c_end=document.cookie.length;
            return unescape(document.cookie.substring(c_start,c_end));
        }
    }
    return "";
}

function set_cookie(name, value, expires, path) {
    var today = new Date();
    today.setTime(today.getTime());

    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 : "" )
}

function switch_fontsize() {
    switch (fontsize) {
    case 'small':
        set_fontsize('medium')
        break
    case 'medium':
        set_fontsize('large')
        break
    case 'large':
        set_fontsize('small')
        break
    default:
        set_fontsize('medium')
    }
}

function set_fontsize(size) {
    if (size == '') {
        return
    }
    img = document.getElementById('img-fontsize')
    img.src = '/images/fontsize-'+size+'.png'

    load_css_file('/css/'+size+'.css')
    fontsize = size
    set_cookie('fontsize',size,365,'/')
}

function init_fontsize() {
    fontsize = get_cookie('fontsize')
    if (fontsize == '') {
        fontsize = 'small'
    }
    set_fontsize(fontsize)
}

function load_css_file(filename) {
    var fileref = document.createElement("link")

    fileref.setAttribute("rel", "stylesheet")
    fileref.setAttribute("type", "text/css")
    fileref.setAttribute("href", filename)

    document.getElementsByTagName("head")[0].appendChild(fileref)
}