var image_base = new Image();
image_base.src = "images/base.png";
var image1 = new Image();
image1.src = "images/banners/banner_1.jpg";

var image2 = new Image();
image2.src = "images/banners/banner_2.jpg";


var image3 = new Image();
image3.src = "images/banners/banner_3.jpg";
var image4 = new Image();
image4.src = "images/banners/banner_4.jpg";
var image5 = new Image();
image5.src = "images/banners/banner_5.jpg";
var image6 = new Image();
image6.src = "images/banners/banner_6.jpg";
var image7 = new Image();
image7.src = "images/banners/banner_7.jpg";
var image8 = new Image();
image8.src = "images/banners/banner_8.jpg";
var image9 = new Image();
image9.src = "images/banners/banner_9.jpg";
var image10 = new Image();
image10.src = "images/banners/banner_10.jpg";
var image11 = new Image();
image11.src = "images/banners/banner_11.jpg";
var image12 = new Image();
image12.src = "images/banners/banner_12.jpg";


function validateFileType(obj)
{
	var arrayofextensions = new Array(".gif",".png",".jpg","jpeg",".swf",".flv",".pdf");
	var filename = obj.value;

	var ext = filename.substr(filename.length - 4,filename.length);

	var res = false;

	for (var i=0; i < arrayofextensions.length; i++)
	{
		if (arrayofextensions[i] == ext)
		{
			res = true;
			break;
		}
	}

	if (!res)
	{
		alert("Tipo de Ficheiro Invalido");
		obj.value = "";
	}

	return res;

}