function BrowserCheck() {
	var b = navigator.appName
	this.mac = (navigator.appVersion.indexOf('Mac') != -1)
	if (b=="Netscape") this.b = 'ns'
	else if (b=="Microsoft Internet Explorer") this.b = 'ie'
	else this.b = b
	this.version = navigator.appVersion
	this.v = parseInt(this.version)
	this.ns = (this.b=="ns" && this.v>=5)
	this.ns5 = (this.b=="ns" && this.v==5)
	this.ns6 = (this.b=="ns" && this.v==5)
	this.ie = (this.b=="ie" && this.v>=4)
	this.ie4 = (this.version.indexOf('MSIE 4')>0)
	this.ie5 = (this.version.indexOf('MSIE 5')>0)
	if (this.mac) this.ie = this.ie5
	this.ie5mac = (this.ie5 && this.mac);
	this.min = (this.ns||this.ie)
}

is = new BrowserCheck();

if ((is.min == false)||(is.ie5mac)){
	alert('Your browser can\'t handle this page. You need NS6, IE5 (or later) on Windows, or NS6 (or later) on Mac.');
//	history.back();
}


function Card(ID){
	this.elm=document.getElementById(ID);
	this.name=ID;
	this.css=this.elm.style;
	this.elm.style.left = 0 +'px';
	this.elm.style.top = 0 +'px';
	this.HomeL = 0;
	this.HomeT = 0;
	this.tag=-1;
	this.index=-1;
//	this.obj=ID+'Card';
//	eval(this.obj+'=this');
}

function CardGetL(){return parseInt(this.css.left)}
Card.prototype.GetL=CardGetL;

function CardGetT(){return parseInt(this.css.top)}
Card.prototype.GetT=CardGetT;

function CardGetW(){return parseInt(this.elm.offsetWidth)}
Card.prototype.GetW=CardGetW;

function CardGetH(){return parseInt(this.elm.offsetHeight)}
Card.prototype.GetH=CardGetH;

function CardGetB(){return this.GetT()+this.GetH()}
Card.prototype.GetB=CardGetB;

function CardGetR(){return this.GetL()+this.GetW()}
Card.prototype.GetR=CardGetR;

function CardSetL(NewL){this.css.left = NewL+'px'}
Card.prototype.SetL=CardSetL;

function CardSetT(NewT){this.css.top = NewT+'px'}
Card.prototype.SetT=CardSetT;

function CardSetW(NewW){this.css.width = NewW+'px'}
Card.prototype.SetW=CardSetW;

function CardSetH(NewH){this.css.height = NewH+'px'}
Card.prototype.SetH=CardSetH;

function CardInside(X,Y){
	var Result=false;
	if(X>=this.GetL()){if(X<=this.GetR()){if(Y>=this.GetT()){if(Y<=this.GetB()){Result=true;}}}}
	return Result;
}
Card.prototype.Inside=CardInside;

function CardSwapColours(){
	var c=this.css.backgroundColor;
	this.css.backgroundColor=this.css.color;
	this.css.color=c;
}
Card.prototype.SwapColours=CardSwapColours;

function CardHighlight(){
	this.css.backgroundColor='#333366';   // or #333388
	this.css.color='#bbbbee';
}
Card.prototype.Highlight=CardHighlight;

function CardUnhighlight(){
	this.css.backgroundColor='#bbbbee';
	this.css.color='#000000';
}
Card.prototype.Unhighlight=CardUnhighlight;

function CardOverlap(OtherCard){
	var smR=(this.GetR()<(OtherCard.GetR()+10))? this.GetR(): (OtherCard.GetR()+10);
	var lgL=(this.GetL()>OtherCard.GetL())? this.GetL(): OtherCard.GetL();
	var HDim=smR-lgL;
	if (HDim<1){return 0;}
	var smB=(this.GetB()<OtherCard.GetB())? this.GetB(): OtherCard.GetB();
	var lgT=(this.GetT()>OtherCard.GetT())? this.GetT(): OtherCard.GetT();
	var VDim=smB-lgT;
	if (VDim<1){return 0;}
	return (HDim*VDim);	
}
Card.prototype.Overlap=CardOverlap;

function CardDockToR(OtherCard){
	this.SetL(OtherCard.GetR() + 5);
	this.SetT(OtherCard.GetT());
}

Card.prototype.DockToR=CardDockToR;

function CardSetHome(){
	this.HomeL=this.GetL();
	this.HomeT=this.GetT();
}
Card.prototype.SetHome=CardSetHome;

function CardGoHome(){
	this.SetL(this.HomeL);
	this.SetT(this.HomeT);
}

Card.prototype.GoHome=CardGoHome;



function PageDim(){
//Get the page width and height
	this.W = 600;
	this.H = 400;
	 if (is.ns) this.W = window.innerWidth;
	 if (is.ie) this.W = document.body.clientWidth;
	 if (is.ns) this.H = window.innerHeight;
	 if (is.ie) this.H = document.body.clientHeight;
}


function PageDim(){
	this.W = newDefaultWidth;
	this.H = newDefaultHeight;
	// Mk April 2007 set width and height used instead of browser-based window and document calculation
}



//Fixed and draggable card arrays
FC = new Array();
DC = new Array();

function doDrag(e) {
	if (CurrDrag == -1) {return};
	if (is.ie){var Ev = window.event}else{var Ev = e}
	var difX = Ev.clientX-window.lastX; 
	var difY = Ev.clientY-window.lastY; 
	var newX = DC[CurrDrag].GetL()+difX; 
	var newY = DC[CurrDrag].GetT()+difY; 
	DC[CurrDrag].SetL(newX); 
	DC[CurrDrag].SetT(newY);
	window.lastX = Ev.clientX; 
	window.lastY = Ev.clientY; 
	return false;
} 


function beginDrag(e, DragNum) { 
	CurrDrag = DragNum;
	if (is.ie){
		var Ev = window.event;
		document.onmousemove=doDrag;
		document.onmouseup=endDrag;
	}
	else{
		var Ev = e;
		window.onmousemove=doDrag; 
		window.onmouseup=endDrag;
	} 
	DC[CurrDrag].Highlight();
	topZ++;
	DC[CurrDrag].css.zIndex = topZ;
	window.lastX=Ev.clientX; 
	window.lastY=Ev.clientY;
	return true;  
} 

function endDrag(e) { 
	if (CurrDrag == -1) {return};
	DC[CurrDrag].Unhighlight();
	if (is.ie){document.onmousemove=null}else{window.onmousemove=null;}
	onEndDrag();	
	CurrDrag = -1;
	return true;
} 

function onEndDrag(){ 
//Is it dropped on any of the fixed cards?
	var Docked = false;
	var DropTarget = DroppedOnFixed(CurrDrag);
	if (DropTarget > -1){
//If so, send home any card that is currently docked there
		for (var i=0; i<DC.length; i++){
			if (DC[i].tag == DropTarget+1){
				DC[i].GoHome();
				DC[i].tag = 0;
				D[i][2] = 0;
			}
		}
//Dock the dropped card
		DC[CurrDrag].DockToR(FC[DropTarget]);
		D[CurrDrag][2] = F[DropTarget][1];
		DC[CurrDrag].tag = DropTarget+1;
		Docked = true;
	}

	if (Docked == false){
		DC[CurrDrag].GoHome();
		DC[CurrDrag].tag = 0;
		D[CurrDrag][2] = 0;
	}
} 

function DroppedOnFixed(DNum){
	var Result = -1;
	var OverlapArea = 0;
	var Temp = 0;
	for (var i=0; i<FC.length; i++){
		Temp = DC[DNum].Overlap(FC[i]);
		if (Temp > OverlapArea){
			OverlapArea = Temp;
			Result = i;
		}
	}
	return Result;
}

function StartUp(){

//Calculate page dimensions and positions
	pg = new PageDim();

//Shuffle the items on the right
	D = Shuffle(D);

	var CurrTop = DragTop;
	var TempInt = 0;
	var DropHome = 0;
	var Widest = 0;

	for (var i=0; i<F.length; i++){
		FC[i] = new Card('F' + i);
//		FC[i].SetW(DragWidth);
		FC[i].elm.innerHTML = F[i][0] + '<br clear="all" />'; //required for Navigator rendering bug with images

		if (FC[i].GetW() > Widest){
			Widest = FC[i].GetW();
		}
	}

	if (Widest > DragWidth){Widest = DragWidth;}

	CurrTop = DragTop;

	DragWidth = Math.floor((DivWidth-Widest)/2) - 24;
	RightColPos = DivWidth + LeftColPos - (DragWidth + 14);
	
	
	var Highest = 0;
	var WidestRight = 0;

	for (i=0; i<D.length; i++){
		DC[i] = new Card('D' + i);
		DC[i].elm.innerHTML = D[i][0] + '<br clear="all" />'; //required for Navigator rendering bug with images
		if (DC[i].GetW() > DragWidth){DC[i].SetW(DragWidth);}
		DC[i].css.cursor = 'move';
		DC[i].css.backgroundColor = '#bbbbee';   // cardBG  
		DC[i].css.color = '#000000';
		TempInt = DC[i].GetH();
		if (TempInt > Highest){Highest = TempInt;}
		TempInt = DC[i].GetW();
		if (TempInt > WidestRight){WidestRight = TempInt;}
	}


	var HeightToSet = Highest;
	if (is.ns||is.ie5mac){HeightToSet -= 12;}
	var WidthToSet = WidestRight;
	if (is.ns||is.ie5mac){WidthToSet -= 12;}

	for (i=0; i<D.length; i++){
		DC[i].SetT(CurrTop);
		DC[i].SetL(RightColPos);
		if (DC[i].GetH() < Highest){
			DC[i].SetH(HeightToSet);
		}
		if (DC[i].GetW() < WidestRight){
			DC[i].SetW(WidthToSet);
		}
		DC[i].SetHome();
		DC[i].tag = -1;
		CurrTop = CurrTop + DC[i].GetH() + 5;
	}

	CurrTop = DragTop;

	for (var i=0; i<F.length; i++){
		FC[i].SetW(Widest);
		if (FC[i].GetH() < Highest){
			FC[i].SetH(HeightToSet);
		}
		FC[i].SetT(CurrTop);
		FC[i].SetL(LeftColPos);
		FC[i].SetHome();
		TempInt = FC[i].GetH();
		CurrTop = CurrTop + TempInt + 5;
	}


//Slide any elements that should be in position over
	for (i=0; i<D.length; i++){
		if (D[i][2] > 0){
			DC[i].tag = D[i][1];
			D[i][2] = D[i][1];
			var TopChange = 0;
			var TargetLeft = FC[D[i][2]-1].GetR() + 5;
			var TargetTop = FC[D[i][1]-1].GetT();
			if (TargetTop < DC[i].GetT()){
				TopChange = -1;
			}
			else {
				if (TargetTop > DC[i].GetT()){
					TopChange = 1;
				}
			}
			Slide(i, TargetLeft, TargetTop, TopChange);
		}
	}

}



function Slide(MoverNum, TargL, TargT, TopChange){
	var TempInt = DC[MoverNum].GetL();
	if (TempInt > TargL){
		DC[MoverNum].SetL(TempInt - 5);
	}
	TempInt = DC[MoverNum].GetT();
	if (TempInt != TargT){
		DC[MoverNum].SetT(TempInt + TopChange);
	}
	if ((DC[MoverNum].GetL() > TargL)||(DC[MoverNum].GetT() != TargT)){
		setTimeout('Slide('+MoverNum+','+TargL+','+TargT+','+TopChange+')', 1);
	}
	else{
		DC[MoverNum].SetL(TargL);
	}
}