var delimeter = "-";

function getParams()
{
    var idx = document.URL.indexOf('?');
    var params = new Array();
    if (idx != -1)
    {
        var pairs = document.URL.substring(idx+1, document.URL.length).split('&');
        for(var i=0;i < pairs.length; i++)
        {
            nameVal = pairs[i].split('=');
			if (isValidKeyValuePair(nameVal))
			{
				params[nameVal[0]] = nameVal[1];
			}
        }
    }
    return params;
}

// Determines whether a param pair is valid and should be added to param list
function isValidKeyValuePair(kvp)
{
	return nameVal.length == 2 && nameVal[0] != "" && nameVal[0] != undefined && nameVal[1] != undefined;
}

function getParamsbyref()
{
    paramsbyref = getParamsbyrefString(document.URL);
    return paramsbyref;
}

function getParamsbyrefString(url)
{
    var idx = url.indexOf('?');
    var paramsbyref = new Array();
    if (idx != -1)
    {
        var pairs = url.substring(idx+1, url.length).split('&');
		var paramCount = pairs.length;
        for(var i=0;i < paramCount; i++)
        {
            nameVal = pairs[i].split('=');
            if (isValidKeyValuePair(nameVal))
			{
				paramsbyref.push(nameVal);
			}
        }
    }
    return paramsbyref;
}

function setParam(id, value)
{
    paramsbyref=getParamsbyref();
    var url ='not';
    if (document.URL.indexOf('?') == -1)
    {
        url = "?" + id + "=" + value;
    }
    else if (document.URL.indexOf("&" + id + "=") != -1 || document.URL.indexOf("?" + id + "=") != -1)
    {
        url = "?";
        for (var i = 0; i < paramsbyref.length; i++)
        {
            if (i != 0)
                url +="&";
            url += paramsbyref[i][0] + "=";
            if (paramsbyref[i][0].toLowerCase() != id.toLowerCase())
                url += paramsbyref[i][1];
            else
                url += value;
        }
        if (id.toLowerCase() != 'pagenum')
        {
        url = removeParamString("pagenum", url);
        }
    }
    else
    {
        var idx = document.URL.indexOf('?');
        url = "?" + document.URL.substring(idx+1, document.URL.length) + "&" + id + "=" + value;
        if (id.toLowerCase() != 'pagenum')
        {
        url = removeParamString("pagenum", url);
        }
    }
    document.location.href = url;
}

function removeParamString(id, instring) {
    if (instring == "")
        paramsbyref=getParamsbyref();
    else
        paramsbyref=getParamsbyrefString(instring);
    var url = "";
    for (var i = 0; i < paramsbyref.length; i++)
    {
        if (paramsbyref[i][0].toLowerCase() != id.toLowerCase())
        {
            if (url.length != 0)
                url +="&";
            else
                url += "?";
            url += paramsbyref[i][0] + "=" +paramsbyref[i][1];
        }
    }
    if(url == "")
    {
        var idx = document.URL.indexOf('?');
        url = document.URL.substring(0, idx);
    }
    return url;
}

function removeParam(id)
{
    var url = removeParamString(id, "");
    document.location.href = url;
}

function reductiveStartOver() {
    var url = removeParamString("section", "");
    url = removeParamString("category", url);
    url = removeParamString("manufacturer", url);
    url = removeParamString("distributor", url);
    url = removeParamString("genre", url);
    url = removeParamString("vector", url);
    document.location.href = url;
}

function sectionLink(sec) {entityLink(sec, "sections");}    // override for backwards compatability
function entityLink(id, paramname)
{
    params = getParams();
    if (params[paramname] != null && params[paramname].match(delimeter + id + delimeter) == delimeter + id + delimeter)
        {return;}
    if (params[paramname] != null)
        var querystring = params[paramname] + id + delimeter;
    else
        var querystring = delimeter + id + delimeter;
    setParam(paramname, querystring);
}

function sectionReplaceLink(sec, oldsec){entityReplaceLink(sec, oldsec, "sections");}//override for backwards compatability
function entityReplaceLink(id, oldid, paramname)
{
    params = getParams();
    if (params[paramname] != null && params[paramname].match(delimeter + id + delimeter) == delimeter + id + delimeter)
        {return;}
        if (params[paramname] != null)
            var querystring = params[paramname].replace(delimeter + oldid + delimeter, delimeter + id + delimeter);
    else
        var querystring = delimeter + id + delimeter;
    setParam(paramname, querystring);
}

function removeSection(id) {removeEntity(id, "sections"); } //override for backwards compatability
function removeEntity(id, paramname)
{
    params = getParams();
    var out = removeID(params[paramname], delimeter + id + delimeter);
    if (out == delimeter)
        removeParam(paramname);
    else
        setParam(paramname, out);
}

function removeID(s, t) 
{
    i = s.indexOf(t);
    r = "";
    if (i == -1) return s;
        r += s.substring(0,i) + delimeter + removeID(s.substring(i + t.length), t);
    return r;
}

function replaceBasePage(newpage) {
    var idx = document.URL.indexOf('?');
    var qs = '';
    if (idx > 0) {
        qs = document.URL.substring(idx, document.URL.length);
    }
    document.location.href = newpage + qs;
}




//Cookie Code
function getCookie(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 setCookie(c_name,value,expiredays)
{
var exdate=new Date()
exdate.setDate(exdate.getDate()+expiredays)
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
}

function checkCookie()
{
username=getCookie('username')
if (username!=null && username!="")
  {alert('Welcome again '+username+'!')}
else 
  {
  username=prompt('Please enter your name:',"")
  if (username!=null && username!="")
    {
    setCookie('username',username,365)
    }
  }
}

function show(sid, name, sectionname) {showEntity(sid, name, sectionname, "sections"); } //override for backwards compatability
function showEntity(id, name, entityname, paramname)
{
    if (params[paramname] != null && params[paramname].match(delimeter + id + delimeter) == delimeter + id + delimeter)
    { selectedArray.push([id, name, entityname]); }
    document.getElementById(entityname+"Header").style.display="block";
}


var selectedArray = new Array();
var showSelected = false;
params = getParams();