// initialize some global variables
var ie = (document.all) ? true : false;
var nn = (document.layers) ? true : false;

// OBJECT DEFINITION:      Drag
function Drag(lyrid) {
	this.css = (nn) ? document.layers[lyrid] : document.all[lyrid];
	this.layerid = lyrid;
	this.startX =  null;
	this.startY = null;
	this.width =  null;
	this.height =  null;
	this.offsetX = null;
	this.offsetY = null;
	this.upperlimit = -1000;
	this.leftlimit = -4000;
	this.lastclicked = 0;
	this.z = (nn) ? this.css.zIndex : this.css.style.zIndex;
}
if (ie) {
	Drag.prototype.shiftTo = function(newX, newY) {
		if (this.leftlimit > newX ) newX = this.leftlimit;
		if (this.upperlimit > newY) newY = this.upperlimit;
		this.css.style.pixelLeft = newX;
		this.css.style.pixelTop =  newY;
	}
	Drag.prototype.clipTo = function(left, top, right, bottom) {
		var rectstring = "rect("+top+","+right+","+bottom+","+left+")";
		this.css.style.clip = rectstring;	
	}
	Drag.prototype.show = function() {	this.css.style.visibility = "inherit"; }
	Drag.prototype.hide = function() {	this.css.style.visibility = "hidden"; }
	Drag.prototype.getX = function(e) {	   return event.x + document.body.scrollLeft; }
	Drag.prototype.getY = function(e) {	   return event.y + document.body.scrollTop; }
	Drag.prototype.getLeft = function() { 	return this.css.style.pixelLeft; }
	// IE 5 on a PC always returns 0 this unless the layer has been moved.
	Drag.prototype.getTop = function() {	return  this.css.style.pixelTop; }
	Drag.prototype.getWidth = function() {	return  this.css.clientWidth; }
	Drag.prototype.getHeight = function() {	return  this.css.clientHeight; }
	Drag.prototype.getVisibility = function() {	return this.css.style.visibility; }
	Drag.prototype.setZIndex = function(z) {	this.css.style.zIndex = z; }
	Drag.prototype.writeIt = function(stuff) {	this.css.innerHTML = stuff; }
	Drag.prototype.images = function(item) {	
		if (item) return document.all[item]; return document.all; }
	Drag.prototype.forms = function(item) {	
		if (item) return document.forms[item]; return document.forms; }
	Drag.prototype.setLastClicked = function() {
		// will not work in IE.  use the onDblClick event in <a href>
	}
	Drag.prototype.wasDoubleClicked = function() {
		// will not work in IE.  use the onDblClick event in <a href>
	}
}
if (nn) {
	Drag.prototype.shiftTo = function(newX, newY) {
		if (this.leftlimit > newX ) newX = this.leftlimit;
		if (this.upperlimit > newY) newY = this.upperlimit;
		this.css.moveTo(newX, newY);
	}
	Drag.prototype.clipTo = function(left, top, right, bottom) {
		this.css.clip.left = left;
		this.css.clip.width = right;
		this.css.clip.top = top;
		this.css.clip.bottom = bottom;
	}
	Drag.prototype.show = function() {	this.css.visibility = "show"; }
	Drag.prototype.hide = function() {	this.css.visibility = "hide"; }
	Drag.prototype.getX = function(e) {	   return e.pageX; }
	Drag.prototype.getY = function(e) {	   return e.pageY; }
	Drag.prototype.getLeft = function() {	return  this.css.left; }
	Drag.prototype.getTop = function() {	return  this.css.top; }
	Drag.prototype.getWidth = function() {	return  this.css.clip.width; }
	Drag.prototype.getHeight = function() {	return  this.css.clip.height; }
	Drag.prototype.getVisibility = function() {	return this.css.visibility; }
	Drag.prototype.setZIndex = function(z) {	this.css.zIndex = z; }
	Drag.prototype.writeIt = function(stuff) {	this.css.document.write(stuff); }
	Drag.prototype.images = function(item) {	
		if (item) return this.css.document.images[item];
		return this.css.document.images; }
	Drag.prototype.forms = function(item) {	
		if (item) return this.css.document.forms[item];
		return this.css.document.forms; }
	Drag.prototype.setLastClicked = function() {
		// will not work in IE.  use the onDblClick event in <a href>
		this.lastclicked = new Date().getTime();
	}
	Drag.prototype.wasDoubleClicked = function() {
		// will not work in IE.  use the onDblClick event in <a href>
		var thisClick = new Date().getTime();
		var delta = thisClick - this.lastclicked;
		this.setLastClicked();
		if (delta > 0 && delta < 500) return true;
		return false;
	}
}
Drag.prototype.getRight = function() {	return  this.getLeft() + this.getWidth(); }
Drag.prototype.isVisible= function() {
   var vState = this.getVisibility();
   if (vState == 'hide' || vState == 'hidden') return false;
   return true;
}
Drag.prototype.setEngage = function(e) {
	// 1) record where on the object it click was
	// 2) set z-index arbitrarily high (i.e., 100) so it floats over everything else
	this.startX = this.getX(e);
	this.startY = this.getY(e);
	this.setOffset(e);
	this.setZIndex(300);
	if (nn) document.captureEvents( Event.MOUSEMOVE );
	if (nn) document.captureEvents( Event.MOUSEUP );
}
Drag.prototype.setRelease = function(e) {
//	this.setZIndex(this.z);
	if (nn) document.releaseEvents( Event.MOUSEMOVE );
	if (nn) document.releaseEvents( Event.MOUSEUP );
}
Drag.prototype.dragIt = function(x,y) {
	this.shiftTo(x, y);
}
Drag.prototype.setStartCoord = function() {
	this.startX = this.getLeft(); 
	this.startY = this.getTop();
}
Drag.prototype.setOffset = function(e) {
		this.offsetX = this.getX(e) - this.getLeft();
		this.offsetY = this.getY(e) - this.getTop();
}
Drag.prototype.wasClicked = function(e) {
   var x = this.getX(e);
   var y = this.getY(e);
   this.isWithin(x, y);
}
Drag.prototype.isWithin = function(x, y) {
	var myLeft = this.getLeft();
	var myRight = myLeft + this.getWidth();
	var myTop = this.getTop();
	var myBottom = myTop + this.getHeight();
	if ( x>=myLeft && x<myRight && y>=myTop && y<myBottom ) return true;
	else return false;
}