/* Functions to control scroll position */
function saveScrollCoordinates(link) { 

    var sy = document.body.scrollTop;
    if (sy == 0)
    {
        if (window.pageYOffset)
            sy = window.pageYOffset;
        else
            sy = (document.body.parentElement) ? document.body.parentElement.scrollTop : 0;
    }

    var sx = document.body.scrollLeft;
    if (sx == 0)
    {
        if (window.pageXOffset)
            sx = window.pageXOffset;
        else
            sx = (document.body.parentElement) ? document.body.parentElement.scrollLeft : 0;
    }

    link.href = link.href + "&sx=" + sx + "&sy=" + sy;
} 

function scrollToPreservedPosition() {

    var qs = new Querystring();
    
    if (qs.get("sx")!=null && qs.get("sy")!=null) window.scrollTo(qs.get("sx"), qs.get("sy"));

}

/* Client-side access to querystring name=value pairs
	Version 1.3
	28 May 2008
	
	License (Simplified BSD):
	http://adamv.com/dev/javascript/qslicense.txt
*/
function Querystring(qs) { // optionally pass a querystring to parse
	this.params = {};
	
	if (qs == null) qs = location.search.substring(1, location.search.length);
	if (qs.length == 0) return;

    // Turn <plus> back to <space>
    // See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
	qs = qs.replace(/\+/g, ' ');
	var args = qs.split('&'); // parse out name/value pairs separated via &
	
    // split out each name=value pair
	for (var i = 0; i < args.length; i++) {
		var pair = args[i].split('=');
		var name = decodeURIComponent(pair[0]);
		
		var value = (pair.length==2)
			? decodeURIComponent(pair[1])
			: name;
		
		this.params[name] = value;
	}
}

Querystring.prototype.get = function(key, default_) {
	var value = this.params[key];
	return (value != null) ? value : default_;
}

Querystring.prototype.contains = function(key) {
	var value = this.params[key];
	return (value != null);
}