/**
Common add Event listener function
*/
function addListener(element, type, expression, bubbling) {
	bubbling = bubbling || false;
	if(window.addEventListener)	{ // Standard
		element.addEventListener(type, expression, bubbling);
		return true;
	} else if(window.attachEvent) { // IE
		element.attachEvent('on' + type, expression);
		return true;
	} else return false;
}

/**
Prompts the user to confirm before proceeding with an action
*/
function interfaceConfirm(confirmText, targetURL) {
	if(confirm(confirmText)) {
		document.location.href = targetURL;
	}
}

/**
Sets a form field with the focus
*/
function setFieldFocus(field) {
	window.focus();
	if(field) {
		try {
			field.focus();	
		} catch(e) {
			
		}		
	}
}

/**
Sets the first field with focus
*/
function setFirstFieldWithFocus(form, skipFilled) {
	if(form.elements[0] != null) {
		var i;
		var max = form.length;
		for( i = 0; i < max; i++ ) {
			if( form.elements[i].type != "hidden" &&
				!form.elements[i].disabled &&
				!form.elements[i].readOnly && 
				(!skipFilled || (skipFilled && form.elements[i].value == '' ) )) {
				setFieldFocus(form.elements[i]);
				break;
			}
		}
	}
}

function CheckEmail(str) {
	return (str.indexOf(".") >= 1) && (str.indexOf("@") > 0);
}


var Coordinates = {
	ORIGIN : new Coordinate(0, 0),

	northwestPosition : function(element) {
		var x = findPosX(element);
		var y = findPosY(element);
		return new Coordinate(isNaN(x) ? 0 : x, isNaN(y) ? 0 : y);
	},

	southeastPosition : function(element) {
		return Coordinates.northwestPosition(element).plus(
				new Coordinate(element.offsetWidth, element.offsetHeight));
	},

	northwestOffset : function(element, isRecursive) {
		var offset = new Coordinate(element.offsetLeft, element.offsetTop);

		if (!isRecursive) return offset;

		var parent = element.offsetParent;
		while (parent) {
			offset = offset.plus(
					new Coordinate(parent.offsetLeft, parent.offsetTop));
			parent = parent.offsetParent;
		}
		return offset;
	},

	southeastOffset : function(element, isRecursive) {
		return Coordinates.northwestOffset(element, isRecursive).plus(
				new Coordinate(element.offsetWidth, element.offsetHeight));
	},

	fixEvent : function(event) {
		event.windowCoordinate = new Coordinate(event.clientX, event.clientY);
	}
};


function Coordinate(x, y) {
	this.x = x;
	this.y = y;
}

Coordinate.prototype.toString = function() {
	return "(" + this.x + "," + this.y + ")";
}

Coordinate.prototype.plus = function(that) {
	return new Coordinate(this.x + that.x, this.y + that.y);
}

Coordinate.prototype.minus = function(that) {
	return new Coordinate(this.x - that.x, this.y - that.y);
}

Coordinate.prototype.distance = function(that) {
	var deltaX = this.x - that.x;
	var deltaY = this.y - that.y;

	return Math.sqrt(Math.pow(deltaX, 2) + Math.pow(deltaY, 2));
}

Coordinate.prototype.max = function(that) {
	var x = Math.max(this.x, that.x);
	var y = Math.max(this.y, that.y);
	return new Coordinate(x, y);
}

Coordinate.prototype.constrain = function(min, max) {
	if (min.x > max.x || min.y > max.y) return this;

	var x = this.x;
	var y = this.y;

	if (min.x != null) x = Math.max(x, min.x);
	if (max.x != null) x = Math.min(x, max.x);
	if (min.y != null) y = Math.max(y, min.y);
	if (max.y != null) y = Math.min(y, max.y);

	return new Coordinate(x, y);
}

Coordinate.prototype.reposition = function(element) {
	element.style["top"] = this.y + "px";
	element.style["left"] = this.x + "px";
}

Coordinate.prototype.equals = function(that) {
	if (this == that) return true;
	if (!that || that == null) return false;

	return this.x == that.x && this.y == that.y;
}

// returns true of this point is inside specified box
Coordinate.prototype.inside = function(northwest, southeast) {
	if ((this.x >= northwest.x) && (this.x <= southeast.x) &&
		(this.y >= northwest.y) && (this.y <= southeast.y)) {
		
		return true;
	}
	return false;
}

function fixEvent(event) {
	if (typeof event == 'undefined') event = window.event;
	Coordinates.fixEvent(event);
	return event;
}

function getEventTarget(event) {return (window.event) ? event.srcElement : event.target; }



// --------------------------------
function findPosX(obj)
{
	var curleft = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curleft += obj.offsetLeft
			obj = obj.offsetParent;
		}
	}
	else if (obj.x)
		curleft += obj.x;
	return curleft;
}

// --------------------------------
function findPosY(obj)
{
	var curtop = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curtop += obj.offsetTop
			obj = obj.offsetParent;
		}
	}
	else if (obj.y)
		curtop += obj.y;
	return curtop;
}