/* Utilites */
//jsnAddEvent - attach a function to an event
function jsnAddEvent(target, event, func){ 
    if (target.addEventListener){ 
        target.addEventListener(event, func, false); 
        return true; 
    } else if (target.attachEvent){ 
        var result = target.attachEvent("on"+event, func); 
        return result; 
    } else { 
        return false; 
    }
}

function jsnCheckSubstring(targetString, targetSubstring, delimeter)
{
    var parts = targetString.split(delimeter);
    for (var i = 0; i < parts.length; i++){
        if (parts[i] == targetSubstring) return true;
    }
    return false;
}

function jsnGetElementsByClass(targetParent, targetTag, targetClass)
{
    if(!targetParent.getElementsByTagName) return;
    
    var elements, tags;
    
    tags = targetParent.getElementsByTagName(targetTag);
    elements = [];
    
    for(var i=0;i<tags.length;i++){
        if(jsnCheckSubstring(tags[i].className, targetClass, " ")){
            elements[elements.length] = tags[i];
        }
    }
    
    return elements;
}

function jsnDigTag(targetTag, targetName, digLevel)
{
    if(digLevel) {
        var n, d;
        n = targetTag.childNodes;
        for(var i=0;i<n.length;i++){
            d = n[i];
            if(d.tagName == targetName)
                return jsnDigTag(d, targetName, --digLevel);
        }
    }
    return targetTag;
}

function jsnWriteCookie(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 jsnReadCookie(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;
}


/* Menu functions */
function jsnMakeDivMenu(menuClass)
{
    var lists = jsnGetElementsByClass(document, "UL", menuClass);
    for(var i=0;i<lists.length;i++){
        var list = lists[i];
        var listItems;
        
        if(list != undefined) {
            listItems = list.getElementsByTagName("LI");
            listItems[0].style.border = "none";
        }
    }
}

function jsnMakeIconMenu(menuClass, icons)
{
    var lists = jsnGetElementsByClass(document, "UL", menuClass);
    var iconId = 0;
    
    for(var i=0;i<lists.length;i++){
        var list = lists[i];
        var listItems;
        
        if(list != undefined) {
            listItems = list.getElementsByTagName("LI");
            for(var j=0;j<listItems.length;j++){
                listItems[j].firstChild.style.backgroundImage = 'url(' + icons[iconId] + ')';
                iconId = (iconId >= icons.length-1)?1:iconId+1;
            }
        }
    }
}



/* Accessibility functions */
var defaultFontSize = 75;
var currentFontSize = defaultFontSize;
	
function jsnSetFontSize(targetId, fontSize)
{
    var targetObj = (document.getElementById) ? document.getElementById(targetId) : document.all(targetId);
    targetObj.style.fontSize = fontSize + '%';
    console.log (document.body.style.fontSize);
}


function jsnChangeFontSize(sizeDifference)
{
	currentFontSize = parseInt(currentFontSize) + parseInt(sizeDifference * 2.5);

	if(currentFontSize > 100){
		currentFontSize = 100;
	}else if(currentFontSize < 60){
		currentFontSize = 50;
	}
	jsnSetFontSize("jsn-master", currentFontSize);
}

function jsnResetFontSize()
{
	currentFontSize = defaultFontSize;
	jsnChangeFontSize(0);
}