/***********************************************
* AnyLink Drop Down Menu- © Dynamic Drive (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/

var menuwidth='100px' //default menu width
var menubgcolor='#ffffff'  //menu bgcolor
var disappeardelay=250  //menu disappear speed onMouseout (in miliseconds)
var hidemenu_onclick="yes" //hide menu when user clicks within menu?

/////No further editting needed

var ie4=document.all
var ns6=document.getElementById&&!document.all

if (ie4||ns6)
document.write('<div id="dropmenudiv" style="visibility:hidden;width:'+menuwidth+';background-color:'+menubgcolor+'" onMouseover="clearhidemenu()" onMouseout="dynamichide(event)"></div>')

function getposOffset(what, offsettype){
var totaloffset=(offsettype=="left")? what.offsetLeft : what.offsetTop;
var parentEl=what.offsetParent;
while (parentEl!=null){
totaloffset=(offsettype=="left")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;
parentEl=parentEl.offsetParent;
}
return totaloffset;
}


function showhide(obj, e, visible, hidden, menuwidth){
if (ie4||ns6)
dropmenuobj.style.left=dropmenuobj.style.top="-500px"
if (menuwidth!=""){
dropmenuobj.widthobj=dropmenuobj.style
dropmenuobj.widthobj.width=menuwidth
}
if (e.type=="click" && obj.visibility==hidden || e.type=="mouseover")
obj.visibility=visible
else if (e.type=="click")
obj.visibility=hidden
}

function iecompattest(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}

function clearbrowseredge(obj, whichedge){
var edgeoffset=0
if (whichedge=="rightedge"){
var windowedge=ie4 && !window.opera? iecompattest().scrollLeft+iecompattest().clientWidth-15 : window.pageXOffset+window.innerWidth-15
dropmenuobj.contentmeasure=dropmenuobj.offsetWidth
if (windowedge-dropmenuobj.x < dropmenuobj.contentmeasure)
edgeoffset=dropmenuobj.contentmeasure-obj.offsetWidth
}
else{
var topedge=ie4 && !window.opera? iecompattest().scrollTop : window.pageYOffset
var windowedge=ie4 && !window.opera? iecompattest().scrollTop+iecompattest().clientHeight-15 : window.pageYOffset+window.innerHeight-18
dropmenuobj.contentmeasure=dropmenuobj.offsetHeight
if (windowedge-dropmenuobj.y < dropmenuobj.contentmeasure){ //move up?
edgeoffset=dropmenuobj.contentmeasure+obj.offsetHeight
if ((dropmenuobj.y-topedge)<dropmenuobj.contentmeasure) //up no good either?
edgeoffset=dropmenuobj.y+obj.offsetHeight-topedge
}
}
return edgeoffset
}

function populatemenu(what){
if (ie4||ns6)
dropmenuobj.innerHTML=what.join("")
}


function dropdownmenu(obj, e, menucontents, menuwidth){
if (window.event) event.cancelBubble=true
else if (e.stopPropagation) e.stopPropagation()
clearhidemenu()
dropmenuobj=document.getElementById? document.getElementById("dropmenudiv") : dropmenudiv
populatemenu(menucontents)

if (ie4||ns6){
showhide(dropmenuobj.style, e, "visible", "hidden", menuwidth)
dropmenuobj.x=getposOffset(obj, "left")
dropmenuobj.y=getposOffset(obj, "top")
dropmenuobj.style.left=dropmenuobj.x-clearbrowseredge(obj, "rightedge")+"px"
dropmenuobj.style.top=dropmenuobj.y-clearbrowseredge(obj, "bottomedge")+obj.offsetHeight+"px"
}

return clickreturnvalue()
}

function clickreturnvalue(){
if (ie4||ns6) return false
else return true
}

function contains_ns6(a, b) {
while (b.parentNode)
if ((b = b.parentNode) == a)
return true;
return false;
}

function dynamichide(e){
if (ie4&&!dropmenuobj.contains(e.toElement))
delayhidemenu()
else if (ns6&&e.currentTarget!= e.relatedTarget&& !contains_ns6(e.currentTarget, e.relatedTarget))
delayhidemenu()
}

function hidemenu(e){
if (typeof dropmenuobj!="undefined"){
if (ie4||ns6)
dropmenuobj.style.visibility="hidden"
}
}

function delayhidemenu(){
if (ie4||ns6)
delayhide=setTimeout("hidemenu()",disappeardelay)
}

function clearhidemenu(){
if (typeof delayhide!="undefined")
clearTimeout(delayhide)
}

if (hidemenu_onclick=="yes")
document.onclick=hidemenu


/// for Netter's moving the changes for ISBN13 from rollover.js to dropdownmenu.js
function Convertisbnhd(from,to,isbn) {
    //alert("Entered ISBN is : "+isbn);
    var i = 0;
    var v = 0;
    var n = 0;
    var c = "";
    var Result = "";
    var s12 = "";
    //var ISBN10 = document.FrmConv.TxtISBN10.value;
    var ISBN10 = isbn;
    var len = ISBN10.length;
    if (len<9 || len>10)
        //Result = "ERROR";
        Result=isbn;
    else
    {
        s12 = "978" + ISBN10.substring(0, 9);
        for (i=0; i<12; i++)
        {
            if (Result=="")
                {
                    c = s12.charAt(i);
                    if (c>="0" && c<="9")
                    {
                        v = c - 0;
                        if ((i % 2)!=0)
                            v = 3 * v;
                        n = n + v;
                    }
                    else
                        //Result = "ERROR"
                        Result=isbn
                }
        }
        if (Result=="")
        {
            n = n % 10;
            if (n!=0)
                n = 10 - n;
            Result = s12 + n;
        }
    }
    //document.FrmConv.TxtISBN13.value = Result;
    return Result;
}
//Added by DB for ISBN
//Checks whether the search string consists of 0-9 numbers,X,x and -
function isValidISBNhd(str)
{
    var valid="0123456789X-x";
    str=trimhd(str);
    for (var i=0; i<str.length; i++) {
        if (valid.indexOf(str.charAt(i)) < 0) {
            return false;
        }
    }
    return true;
}
//Added by DB for ISBN
//Trims the string by removing left and right leading white spaces
function trimhd(str)
{
    return str.replace(/^\s*|\s*$/g,"");
}

function checkquicksearch() {
    //Modified by DB for ISBN
    var pivotword="";
    pivotword=trimhd(document.quicksearch.searchvalue.value);
    if(!pivotword || isWhitespace(pivotword)) {
        alert('Please enter your search criterion');
        document.quicksearch.searchvalue.focus();
        return false;
    }
    else if( isValidISBNhd(pivotword) == true )
    {
        pivotword=pivotword.replace(/-/g,"");
        if(pivotword.length != 10 && pivotword.length != 13 && pivotword.length != 8 )
        {
              //alert("Enter a valid ISBN");
              //return false;
              return true;
        }
        else if(pivotword.length == 10 )
        {
              //pivotword = Convertisbnhd(10,13,pivotword);
              document.quicksearch.searchvalue.value=pivotword;
              return true;
        }
        else if (pivotword.length == 13 || pivotword.length == 8 )
        {
              document.quicksearch.searchvalue.value=pivotword;
              return true;
        }
     }
     else {
           return true;
     }
}

function submitquickform() {
    if (checkquicksearch() == true) {
        document.quicksearch.submit();
    }
}

// whitespace characters
var whitespace = " \t\n\r";
function isWhitespace (s){
    var i;
    for (i = 0; i < s.length; i++){
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (whitespace.indexOf(c) == -1) return false;
    }
    // All characters are whitespace.
    return true;
}