//---thanks to alistapart

//-----------------------------------------------------------------------------rerender

function rerender(x) {
    w = 100 - 0.0001 * (x);
    document.getElementById('header').style.width = w + '%';
}

//-----------------------------------------------------------------------------cookie functions

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 + "; path=/";
}

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;
}

//-----------------------------------------------------------------------------getActiveStyleSheet

function getActiveStyleSheet() {
    href = document.getElementById("ctl00_bodyCSS").href;
    x = href.lastIndexOf('/') + 1;
    y = href.lastIndexOf('.')
    cssFileName = href.substring(x, y);
    return cssFileName;
}

//-----------------------------------------------------------------------------getPreferredStyleSheet

function getPreferredStyleSheet() {
    var i, a;
    for (i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
        if (a.getAttribute("rel").indexOf("style") != -1
      && a.getAttribute("rel").indexOf("alt") == -1
      && a.getAttribute("title")
      )
            alert(a.getAttribute("title"));

        return a.getAttribute("title");
    }
    return null;
}

//-----------------------------------------------------------------------------changeFontSize

function changeFontSize(fontSize) {
    var cssFileName;
    switch (fontSize) {
        case 1: cssFileName = 'smallfont'; break;
        case 2: cssFileName = 'mediumfont'; break;
        case 3: cssFileName = 'largefont'; break;
    }
    href = '/_layouts/RNIB/Internet/Styles/TextResizing/' + cssFileName + '.css';
    document.getElementById("ctl00_bodyCSS").href = href;
    rerender(fontSize);
}

//-----------------------------------------------------------------------------onLoad

window.onload = function(e) {
    var cookie = readCookie("style");
    var title = cookie ? cookie : getActiveStyleSheet();
    if (cookie != null) { setActiveStyleSheet(title); }
    rerender(4);
}

function setActiveStyleSheet(cssFileName) {
    href = '/_layouts/RNIB/Internet/Styles/TextResizing/' + cssFileName + '.css';
    //alert (href);
    document.getElementById("ctl00_bodyCSS").href = href;
    return null;
}

window.onunload = function(e) {
    var title = getActiveStyleSheet();
    createCookie("style", title, 365);
}

function displayFontSizeButtons() {

    var html = '<ul class="right">' +

    '<li><a class="small" onclick="javascript:changeFontSize(1); return false;" href="_layouts/RNIB/Internet/JavaScriptError.aspx" alt="small text">' +

    '<img alt="small text" src="/_layouts/RNIB/Internet/Images/smallA.gif" /></a></li>' +

    '<li><a class="medium" onclick="javascript:changeFontSize(2); return false;" href="_layouts/RNIB/Internet/JavaScriptError.aspx" alt="medium text">' +

    '<img alt="medium text" src="/_layouts/RNIB/Internet/Images/mediumA.gif" /></a></li>' +

    '<li><a class="large" onclick="javascript:changeFontSize(3); return false;" href="_layouts/RNIB/Internet/JavaScriptError.aspx" alt="large text">' +

    '<img alt="large text" src="/_layouts/RNIB/Internet/Images/largeA.gif" /></a></li></ul><div class="clear">&nbsp;</div>';

    div = document.getElementById('divTextResizing');
    if (div) {
        div.innerHTML += html;
    }
    else {
        return;
    }

}