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 var 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;
}

function switch_style(css_title) {
    
    var i, link_tag;
    for (i = 0, link_tag = document.getElementsByTagName("link");
    i < link_tag.length; i++) {
        if ((link_tag[i].rel.indexOf("stylesheet") != -1) &&
      link_tag[i].title) {
            link_tag[i].disabled = true;
            if (link_tag[i].title == css_title) {
                link_tag[i].disabled = false;
            }
        }
       
    }
}

function SetStyleSheet(stylesheet) {

    createCookie("StyleSheet", stylesheet,null);
    switch_style(stylesheet);
}


function ToggleTextSize() {
    var cookievalue = readCookie("StyleSheet");
    var text = document.getElementById("textSizeIcon");

    if (cookievalue == null || cookievalue == "standard") 
    {       
        text.innerHTML = "Standard text";
        SetStyleSheet("TextSizeLarger");        
    }
    else 
    {      
        text.innerHTML = "Larger text";
        SetStyleSheet("standard"); 
    }

    text.title = text.innerHTML;
}



function setStyleFromCookie() {
    var cookievalue = readCookie("StyleSheet");
    if (cookievalue != null) {
        
        switch_style(cookievalue);
    }
    else {
        
    }
}
function WriteTextSizeIcons() {

    var cookievalue = readCookie("StyleSheet");
    var outputLink = (cookievalue == null || cookievalue == "standard") ? "Larger text" : "Standard text";

    document.write('<li>|</li><li><a title="' + outputLink + '" href="javascript:ToggleTextSize()" id="textSizeIcon">' + outputLink + '</a></li>');
        
}

//stylesheets must be loaded before this
setStyleFromCookie();

//how to use
//Reference large text style sheet
//<link href="TextSizeLarger.css" rel="alternate stylesheet" type="text/css" title="TextSizeLarger">
//then ref this script file
//<script type='text/javascript' src='V6-2010.js'></script>
//then in the main body chose the suitable place for the link to change text size
//<script type="text/javascript">WriteTextSizeIcons();</script>
//example of the TextSizeLarger.css
//body
//{
  //  font-size:120%; 
//}