function AutoSuggestControl (oTextbox, oProvider) {
	this.cur = -1;
	this.layer = null;
	this.provider = oProvider;
	this.textbox = oTextbox;
	this.init();
}

AutoSuggestControl.prototype.selectRange = function(iStart, iLength) {
	if (this.textbox.createTextRange) {
		var oRange = this.textbox.createTextRange();
		oRange.moveStart("character", iStart);
		oRange.moveEnd("character", iLength - this.textbox.value.length);
		oRange.select();		
	} else if (this.textbox.setSelectionRange) {
		this.textbox.setSelectionRange(iStart, iLength);
	}
	this.textbox.focus();
};

AutoSuggestControl.prototype.typeAhead = function(sSuggestion) {
	if (this.textbox.createTextRange || this.textbox.setSelectionRange) {
		var iLen = this.textbox.value.length;
		this.textbox.value = sSuggestion;
		this.selectRange(iLen, sSuggestion.length);
	}
};

AutoSuggestControl.prototype.autosuggest = function(aSuggestions, bTypeAhead) {
	
	if (aSuggestions && aSuggestions.length > 0) {
		if (bTypeAhead) {
			this.typeAhead(aSuggestions[0]);
		}
		this.showSuggestions(aSuggestions);		
	} else {
		this.hideSuggestions();
	}	
};

AutoSuggestControl.prototype.handleKeyUp = function(oEvent) {
	var iKeyCode = oEvent.keyCode;
	
	if (iKeyCode == 8 || iKeyCode == 46) {
		//backspace o delete keys
		this.provider.requestSuggestions(this, false);
	} else if (iKeyCode < 32 || (iKeyCode >= 33 && iKeyCode <= 46) || (iKeyCode >= 112 && iKeyCode <= 123)) {
		// ignoramos
	} else {
		this.cur = -1;
		this.provider.requestSuggestions(this, true);
	}
};

AutoSuggestControl.prototype.handleKeyDown = function(oEvent) {
	switch (oEvent.keyCode) {
		case 38: //up arrow
			this.prevSuggestion();
			break;
		case 40: //down arrow
			this.nextSuggestion();
			break;
		case 13: //enter
			this.hideSuggestions();
			break;
	}	
};

AutoSuggestControl.prototype.init = function() {
	var oThis = this;
	
	this.textbox.onkeyup = function(oEvent) {
		if (!oEvent) {
			oEvent = window.event;
		}
		oThis.handleKeyUp(oEvent);
	};
	
	this.textbox.onkeydown = function(oEvent) {
		if (!oEvent) {
			oEvent = window.event;
		}
		oThis.handleKeyDown(oEvent);
	};
	
	this.textbox.onblur = function() {
		oThis.hideSuggestions();
	};
	
	this.createDropDown();
};

AutoSuggestControl.prototype.hideSuggestions = function() {
	this.layer.style.visibility = "hidden";	
};

AutoSuggestControl.prototype.highlightSuggestion = function(oSuggestionNode) {
	for (var i = 0; i < this.layer.childNodes.length; i++) {
		var oNode = this.layer.childNodes[i];
		oNode.className = "";
		if (oNode == oSuggestionNode) {
			oNode.className = "current";
		}
	}
};

AutoSuggestControl.prototype.createDropDown = function() { 
	this.layer = document.createElement("div");
	this.layer.className = "suggestions";
	this.layer.style.visibility = "hidden";
	this.layer.style.width = this.textbox.offsetWidth;
	document.body.appendChild(this.layer);
	
	var oThis = this;
	
	this.layer.onmousedown = this.layer.onmouseup = this.layer.onmouseover = function(oEvent) {
		oEvent = oEvent || window.event;
		oTarget = oEvent.target || oEvent.srcElement;		
		
		if (oEvent.type == "mousedown") {		
			if (oTarget.firstChild.nodeValue != null) {
				oThis.textbox.value = oTarget.firstChild.nodeValue;
			}			
			oThis.hideSuggestions();
		} else if (oEvent.type == "mouseover") {
			oThis.highlightSuggestion(oTarget);
		} else {
			oThis.textbox.focus();
		}
	};
};

AutoSuggestControl.prototype.getLeft = function() { 
	var oNode = this.textbox;
	var iLeft = 0;
	
	while (oNode.tagName != "BODY") {
		iLeft += oNode.offsetLeft;
		oNode = oNode.offsetParent;
	}
	return iLeft;
};

AutoSuggestControl.prototype.getTop = function() { 
	var oNode = this.textbox;
	var iTop = 0;
	
	while (oNode.tagName != "BODY") {
		iTop += oNode.offsetTop;
		oNode = oNode.offsetParent;
	}
	return iTop;
};

AutoSuggestControl.prototype.showSuggestions = function(aSuggestions) { 
	var oDiv = null;
	this.layer.innerHTML = "";
	
	for (var i = 0;i < aSuggestions.length; i++) {
		oDiv = document.createElement("div");
		oDiv.appendChild(document.createTextNode(aSuggestions[i]));
		this.layer.appendChild(oDiv);
	}
	
	this.layer.style.left = this.getLeft() + "px";
	this.layer.style.top = (this.getTop() + this.textbox.offsetHeight) + "px";
	this.layer.style.visibility = "visible";
};

AutoSuggestControl.prototype.nextSuggestion = function() { 
	var cSuggestionNodes = this.layer.childNodes;
	
	if (cSuggestionNodes.length > 0 && this.cur < cSuggestionNodes.length - 1) {
		var oNode = cSuggestionNodes[++this.cur];
		this.highlightSuggestion(oNode);
		this.textbox.value = oNode.firstChild.nodeValue;	
	}
};

AutoSuggestControl.prototype.prevSuggestion = function() { 
	var cSuggestionNodes = this.layer.childNodes;
	
	if (cSuggestionNodes.length > 0 && this.cur > 0) {
		var oNode = cSuggestionNodes[--this.cur];
		this.highlightSuggestion(oNode);
		this.textbox.value = oNode.firstChild.nodeValue;	
	}
};