//** Chrome Drop Down Menu- Author: Dynamic Drive (http://www.dynamicdrive.com)
//** Updated: July 14th 06' to v2.0
//1) Ability to "left", "center", or "right" align the menu items easily, just by modifying the CSS property "text-align".
//2) Added an optional "swipe down" transitional effect for revealing the drop down menus.
//3) Support for multiple Chrome menus on the same page.
//** Updated: Nov 14th 06' to v2.01- added iframe shim technique
//** Updated: July 23rd, 08 to v2.4
//1) Main menu items now remain "selected" (CSS class "selected" applied) when user moves mouse into corresponding drop down menu. 
//2) Adds ability to specify arbitrary HTML that gets added to the end of each menu item that carries a drop down menu (ie: a down arrow image).
//3) All event handlers added to the menu are now unobstrusive, allowing you to define your own "onmouseover" or "onclick" events on the menu items.
//4) Fixed elusive JS error in FF that sometimes occurs when mouse quickly moves between main menu items and drop down menus
//** Updated: Oct 29th, 08 to v2.5 (only .js file modified from v2.4)
//1) Added ability to customize reveal animation speed (# of steps)
//2) Menu now works in IE8 beta2 (a valid doctype at the top of the page is required)
var cssdropdown={
disappeardelay: 250, //set delay in miliseconds before menu disappears onmouseout
dropdownindicator: '', //specify full HTML to add to end of each menu item with a drop down menu
enablereveal: [true, 5], //enable swipe effect? [true/false, steps (Number of animation steps. Integer between 1-20. Smaller=faster)]
enableiframeshim: 1, //enable "iframe shim" in IE5.5 to IE7? (1=yes, 0=no)
//No need to edit beyond here////////////////////////
dropmenuobj: null, asscmenuitem: null, domsupport: document.all || document.getElementById, standardbody: null, iframeshimadded: false, revealtimers: {},
getposOffset:function(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;
},
css:function(el, targetclass, action){
var needle=new RegExp("(^|\\s+)"+targetclass+"($|\\s+)", "ig")
if (action=="check")
return needle.test(el.className)
else if (action=="remove")
el.className=el.className.replace(needle, "")
else if (action=="add" && !needle.test(el.className))
el.className+=" "+targetclass
},
showmenu:function(dropmenu, e){
if (this.enablereveal[0]){
if (!dropmenu._trueheight || dropmenu._trueheight<10)
dropmenu._trueheight=dropmenu.offsetHeight
clearTimeout(this.revealtimers[dropmenu.id])
dropmenu.style.height=dropmenu._curheight=0
dropmenu.style.overflow="hidden"
dropmenu.style.visibility="visible"
this.revealtimers[dropmenu.id]=setInterval(function(){cssdropdown.revealmenu(dropmenu)}, 10)
}
else{
dropmenu.style.visibility="visible"
}
this.css(this.asscmenuitem, "selected", "add")
},
revealmenu:function(dropmenu, dir){
var curH=dropmenu._curheight, maxH=dropmenu._trueheight, steps=this.enablereveal[1]
if (curH<maxH){
var newH=Math.min(curH, maxH)
dropmenu.style.height=newH+"px"
dropmenu._curheight= newH + Math.round((maxH-newH)/steps) + 1
}
else{ //if done revealing menu
dropmenu.style.height="auto"
dropmenu.style.overflow="hidden"
clearInterval(this.revealtimers[dropmenu.id])
}
},
clearbrowseredge:function(obj, whichedge){
var edgeoffset=0
if (whichedge=="rightedge"){
var windowedge=document.all && !window.opera? this.standardbody.scrollLeft+this.standardbody.clientWidth-15 : window.pageXOffset+window.innerWidth-15
var dropmenuW=this.dropmenuobj.offsetWidth
if (windowedge-this.dropmenuobj.x < dropmenuW)  //move menu to the left?
edgeoffset=dropmenuW-obj.offsetWidth
}
else{
var topedge=document.all && !window.opera? this.standardbody.scrollTop : window.pageYOffset
var windowedge=document.all && !window.opera? this.standardbody.scrollTop+this.standardbody.clientHeight-15 : window.pageYOffset+window.innerHeight-18
var dropmenuH=this.dropmenuobj._trueheight
if (windowedge-this.dropmenuobj.y < dropmenuH){ //move up?
edgeoffset=dropmenuH+obj.offsetHeight
if ((this.dropmenuobj.y-topedge)<dropmenuH) //up no good either?
edgeoffset=this.dropmenuobj.y+obj.offsetHeight-topedge
}
}
return edgeoffset
},
dropit:function(obj, e, dropmenuID){
if (this.dropmenuobj!=null) //hide previous menu
this.hidemenu() //hide menu
this.clearhidemenu()
this.dropmenuobj=document.getElementById(dropmenuID) //reference drop down menu
this.asscmenuitem=obj //reference associated menu item
this.showmenu(this.dropmenuobj, e)
this.dropmenuobj.x=this.getposOffset(obj, "left")
this.dropmenuobj.y=this.getposOffset(obj, "top")
this.dropmenuobj.style.left=this.dropmenuobj.x-this.clearbrowseredge(obj, "rightedge")+"px"
this.dropmenuobj.style.top=this.dropmenuobj.y-this.clearbrowseredge(obj, "bottomedge")+obj.offsetHeight+1+"px"
this.positionshim() //call iframe shim function
},
positionshim:function(){ //display iframe shim function
if (this.iframeshimadded){
if (this.dropmenuobj.style.visibility=="visible"){
this.shimobject.style.width=this.dropmenuobj.offsetWidth+"px"
this.shimobject.style.height=this.dropmenuobj._trueheight+"px"
this.shimobject.style.left=parseInt(this.dropmenuobj.style.left)+"px"
this.shimobject.style.top=parseInt(this.dropmenuobj.style.top)+"px"
this.shimobject.style.display="block"
}
}
},
hideshim:function(){
if (this.iframeshimadded)
this.shimobject.style.display='none'
},
isContained:function(m, e){
var e=window.event || e
var c=e.relatedTarget || ((e.type=="mouseover")? e.fromElement : e.toElement)
while (c && c!=m)try {c=c.parentNode} catch(e){c=m}
if (c==m)
return true
else
return false
},
dynamichide:function(m, e){
if (!this.isContained(m, e)){
this.delayhidemenu()
}
},
delayhidemenu:function(){
this.delayhide=setTimeout("cssdropdown.hidemenu()", this.disappeardelay) //hide menu
},
hidemenu:function(){
this.css(this.asscmenuitem, "selected", "remove")
this.dropmenuobj.style.visibility='hidden'
this.dropmenuobj.style.left=this.dropmenuobj.style.top="-1000px"
this.hideshim()
},
clearhidemenu:function(){
if (this.delayhide!="undefined")
clearTimeout(this.delayhide)
},
addEvent:function(target, functionref, tasktype){
if (target.addEventListener)
target.addEventListener(tasktype, functionref, false);
else if (target.attachEvent)
target.attachEvent('on'+tasktype, function(){return functionref.call(target, window.event)});
},
startchrome:function(){
if (!this.domsupport)
return
this.standardbody=(document.compatMode=="CSS1Compat")? document.documentElement : document.body
for (var ids=0; ids<arguments.length; ids++){
var menuitems=document.getElementById(arguments[ids]).getElementsByTagName("a")
for (var i=0; i<menuitems.length; i++){
if (menuitems[i].getAttribute("rel")){
var relvalue=menuitems[i].getAttribute("rel")
var asscdropdownmenu=document.getElementById(relvalue)
this.addEvent(asscdropdownmenu, function(){cssdropdown.clearhidemenu()}, "mouseover")
this.addEvent(asscdropdownmenu, function(e){cssdropdown.dynamichide(this, e)}, "mouseout")
this.addEvent(asscdropdownmenu, function(){cssdropdown.delayhidemenu()}, "click")
try{
menuitems[i].innerHTML=menuitems[i].innerHTML+" "+this.dropdownindicator
}catch(e){}
this.addEvent(menuitems[i], function(e){ //show drop down menu when main menu items are mouse over-ed
if (!cssdropdown.isContained(this, e)){
var evtobj=window.event || e
cssdropdown.dropit(this, evtobj, this.getAttribute("rel"))
}
}, "mouseover")
this.addEvent(menuitems[i], function(e){cssdropdown.dynamichide(this, e)}, "mouseout") //hide drop down menu when main menu items are mouse out
this.addEvent(menuitems[i], function(){cssdropdown.delayhidemenu()}, "click") //hide drop down menu when main menu items are clicked on
}
} //end inner for
} //end outer for
if (this.enableiframeshim && document.all && !window.XDomainRequest && !this.iframeshimadded){ //enable iframe shim in IE5.5 thru IE7?
document.write('<IFRAME id="iframeshim" src="about:blank" frameBorder="0" scrolling="no" style="left:0; top:0; position:absolute; display:none;z-index:90; background: transparent;"></IFRAME>')
this.shimobject=document.getElementById("iframeshim") //reference iframe object
this.shimobject.style.filter='progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)'
this.iframeshimadded=true
}
} //end startchrome
}