function AutoCompleteDB()
{
	// set the initial values.
	this.bEnd = false;
	this.nCount = 0;
	this.aStr = new Object;
}

AutoCompleteDB.prototype.add = function(str)
{
	// increment the count value.
	this.nCount++;

	// if at the end of the string, flag this node as an end point.
	if ( str == "" )
		this.bEnd = true;
	else
	{
		// otherwise, pull the first letter off the string
		var letter = str.substring(0,1);
		var rest = str.substring(1,str.length);
		
		// and either create a child node for it or reuse an old one.
		if ( !this.aStr[letter] ) this.aStr[letter] = new AutoCompleteDB();
		this.aStr[letter].add(rest);
	}
}

AutoCompleteDB.prototype.getCount = function(str, bExact)
{
	// if end of search string, return number
	if ( str == "" )
		if ( this.bEnd && bExact && (this.nCount == 1) ) return 0;
		else return this.nCount;
	
	// otherwise, pull the first letter off the string
	var letter = str.substring(0,1);
	var rest = str.substring(1,str.length);
	
	// and look for case-insensitive matches
	var nCount = 0;
	var lLetter = letter.toLowerCase();
	if ( this.aStr[lLetter] )
		nCount += this.aStr[lLetter].getCount(rest, bExact && (letter == lLetter));
	
	var uLetter = letter.toUpperCase();
	if ( this.aStr[uLetter] )
		nCount += this.aStr[uLetter].getCount(rest, bExact && (letter == uLetter));
	
	return nCount;	
}

AutoCompleteDB.prototype.getStrings = function(str1, str2, outStr)
{
	if ( str1 == "" )
	{
		// add matching strings to the array
		if ( this.bEnd ) 
			outStr.push(str2);

		// get strings for each child node
		for ( var i in this.aStr )
			this.aStr[i].getStrings(str1, str2 + i, outStr);
	}
	else
	{
		// pull the first letter off the string
		var letter = str1.substring(0,1);
		var rest = str1.substring(1,str1.length);
		
		// and get the case-insensitive matches.
		var lLetter = letter.toLowerCase();
		if ( this.aStr[lLetter] )
			this.aStr[lLetter].getStrings(rest, str2 + lLetter, outStr);

		var uLetter = letter.toUpperCase();
		if ( this.aStr[uLetter] )
			this.aStr[uLetter].getStrings(rest, str2 + uLetter, outStr);
	}
}

function AutoComplete(aStr, oText, oDiv, nMaxSize)
{
	// initialize member variables
	this.oText = oText;
	this.oDiv = oDiv;
	this.nMaxSize = nMaxSize;
	
	// preprocess the texts for fast access
	this.db = new AutoCompleteDB();
	var i, n = aStr.length;
	for ( i = 0; i < n; i++ )
	{
		this.db.add(aStr[i]);
	}
			
	// attach handlers to the text-box
	oText.AutoComplete = this;
	oText.onkeyup = AutoComplete.prototype.onTextChange;
	oText.onblur = AutoComplete.prototype.onTextBlur;
}

AutoComplete.prototype.onTextBlur = function()
{
	this.AutoComplete.onblur();
}

AutoComplete.prototype.onblur = function()
{
	this.oDiv.style.visibility = "hidden";
}

AutoComplete.prototype.onTextChange = function()
{
	this.AutoComplete.onchange();
}

AutoComplete.prototype.onDivMouseDown = function()
{
	this.AutoComplete.oText.value = this.innerHTML;
}

AutoComplete.prototype.onDivMouseOver = function()
{
	this.className = "AutoCompleteHighlight";
}

AutoComplete.prototype.onDivMouseOut = function()
{
	this.className = "AutoCompleteBackground";
}

AutoComplete.prototype.onchange = function()
{
	var txt = this.oText.value;
	
	// count the number of strings that match the text-box value
	var nCount = this.db.getCount(txt, true);
	
	// if a suitable number then show the popup-div
	if ( (this.nMaxSize == -1 ) || ((nCount < this.nMaxSize) && (nCount > 0)) )
	{
		// clear the popup-div.
		while ( this.oDiv.hasChildNodes() )
			this.oDiv.removeChild(this.oDiv.firstChild);
			
		// get all the matching strings from the AutoCompleteDB
		var aStr = new Array();
		this.db.getStrings(txt, "", aStr);
		
		// add each string to the popup-div
		var i, n = aStr.length;
		for ( i = 0; i < n; i++ )
		{
			var oDiv = document.createElement('div');
			this.oDiv.appendChild(oDiv);
			oDiv.style.cursor = "pointer";
			oDiv.style.width = "100%";
			oDiv.innerHTML = aStr[i];
			oDiv.onmousedown = AutoComplete.prototype.onDivMouseDown;
			oDiv.onmouseover = AutoComplete.prototype.onDivMouseOver;
			oDiv.onmouseout = AutoComplete.prototype.onDivMouseOut;
			oDiv.AutoComplete = this;			
		}
		this.oDiv.style.visibility = "visible";
	}
	else // hide the popup-div
	{
		this.oDiv.innerHTML = "";
		this.oDiv.style.visibility = "hidden";
	}
}

function createAutoCompleteTo()
{
	/*alert(findCtrl('txtCityTo'));
	alert(document.getElementById('myDiv'));*/
	new AutoComplete(
		aNames,
		findCtrl('txtCityTo'), 
		document.getElementById('myDiv'), 
		25
	);
}
function createAutoCompleteFrom()
{
	/*alert(findCtrl('txtCityTo'));
	alert(document.getElementById('myDiv'));*/
	new AutoComplete(
		aNames,
		findCtrl('txtCityFrom'), 
		document.getElementById('fromDiv'), 
		25
	);
}