function init () {

	var botao1_press = new Image();
	var botao1 = new Image();
	botao1_press.src = "images/b3d_home_p.gif";
	botao1.src = "images/b3d_home.gif";

	var botao2_press = new Image();
	var botao2 = new Image();
	botao2_press.src = "images/b3d_servicos_p.gif";
	botao2.src = "images/b3d_servicos.gif";


	var botao3_press = new Image();
	var botao3 = new Image();
	botao3_press.src = "images/b3d_empresas_p.gif";
	botao3.src = "images/b3d_empresas.gif";

	var botao4_press = new Image();
	var botao4 = new Image();
	botao4_press.src = "images/b3d_portfolio_p.gif";
	botao4.src = "images/b3d_portfolio.gif";

	var botao5_press = new Image();
	var botao5 = new Image();
	botao5_press.src = "images/b3d_contactos_p.gif";
	botao5.src = "images/b3d_contactos.gif";

	botoes_menu = new Array(3);
	botoes_menu_press = new Array(3);

	botoes_menu[0] = botao1.src;
	botoes_menu[1] = botao2.src;
	botoes_menu[2] = botao3.src;
	botoes_menu[3] = botao4.src;
	botoes_menu[4] = botao5.src;

	botoes_menu_press[0] = botao1_press.src;
	botoes_menu_press[1] = botao2_press.src;
	botoes_menu_press[2] = botao3_press.src;
	botoes_menu_press[3] = botao4_press.src;
	botoes_menu_press[4] = botao5_press.src;
}

function botao_press (img) {
	if (img.src == botoes_menu[0]) {
		img.src = botoes_menu_press[0];
		return true;
	}

	if (img.src == botoes_menu[1]) {
		img.src = botoes_menu_press[1];
		return true;
	}

	if (img.src == botoes_menu[2]) {
		img.src = botoes_menu_press[2];
		return true;
	}
	
	if (img.src == botoes_menu[3]) {
		img.src = botoes_menu_press[3];
		return true;
	}

	if (img.src == botoes_menu[4]) {
		img.src = botoes_menu_press[4];
		return true;
	}
}


function botao_unpress (img) {

	if (img.src == botoes_menu_press[0]) {
		img.src =  botoes_menu[0];
		return true;
	}

	if (img.src == botoes_menu_press[1]) {
		img.src =  botoes_menu[1];
		return true;
	}

	if (img.src == botoes_menu_press[2]) {
		img.src =  botoes_menu[2];
		return true;
	}

	if (img.src == botoes_menu_press[3]) {
		img.src =  botoes_menu[3];
		return true;
	}

	if (img.src == botoes_menu_press[4]) {
		img.src =  botoes_menu[4];
		return true;
	}
}