//function to retrieve values from the querystring
function QueryString(qs)
{

    var fullUrl, fullQS, arrQS, arrQS2
    
    fullUrl = window.location.toString();
    fullQS = fullUrl.substring(fullUrl.indexOf('?')+1,fullUrl.length);
    arrQS = fullQS.split("&");
        
    for(i=0; i < arrQS.length; i++)
    {
        arrQS2 = arrQS[i].split("=");
        if(arrQS2[0]==qs) {return arrQS2[1];}
    }
}

//overload function to retrieve values from the querystring of specified url
function QueryString(url, qs)
{
    var fullUrl, fullQS, arrQS, arrQS2
    
    fullUrl = url;
    fullQS = fullUrl.substring(fullUrl.indexOf('?')+1,fullUrl.length);
    arrQS = fullQS.split("&");
        
    for(i=0; i < arrQS.length; i++)
    {
        arrQS2 = arrQS[i].split("=");
        if(arrQS2[0]==qs) {return arrQS2[1];}
    }
}

//the following functions are used for encoding and decoding url's and querystrings
//for example, in a url a space is shown as %20, by using Url.decode(string), this will
//be converted back to a space.
var Url = {   
    encode : function (string) {   
        return escape(this._utf8_encode(string));   
    },   
    decode : function (string) {   
        return this._utf8_decode(unescape(string));   
    },   
    _utf8_encode : function (string) {   
        string = string.replace(/\r\n/g,"\n");   
        var utftext = "";   
        for (var n = 0; n < string.length; n++) {   
            var c = string.charCodeAt(n);   
            if (c < 128) {   
                utftext += String.fromCharCode(c);   
            }   
            else if((c > 127) && (c < 2048)) {   
                utftext += String.fromCharCode((c >> 6) | 192);   
                utftext += String.fromCharCode((c & 63) | 128);   
            }   
            else {   
                utftext += String.fromCharCode((c >> 12) | 224);   
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);   
                utftext += String.fromCharCode((c & 63) | 128);   
            }   
        }   
        return utftext;   
    },   
    _utf8_decode : function (utftext) {   
        var string = "";   
        var i = 0;   
        var c = c1 = c2 = 0;   
        while ( i < utftext.length ) {   
            c = utftext.charCodeAt(i);   
            if (c < 128) {   
                string += String.fromCharCode(c);   
                i++;   
            }   
            else if((c > 191) && (c < 224)) {   
                c2 = utftext.charCodeAt(i+1);   
                string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));   
                i += 2;   
            }   
            else {   
                c2 = utftext.charCodeAt(i+1);   
                c3 = utftext.charCodeAt(i+2);   
                string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));   
                i += 3;   
            }   
        }   
        return string;   
    }   
}

//string trim function
function trim(str) 
{ 
    if (typeof str != "string") return str; 
    str = str.replace(/^\s+|\s+$/g, ""); 
    return str;
}