$(document).ready(function(){
	$("#busca_txt").keypress(function (e) {
		if (e.which == 13)
			$("#btn_buscar").click();
	});
										
	$("#btn_buscar").click(function(){
		if ($("#busca_txt").val().length > 0)
			location.href = "loja_virtual.php?busca_txt="+$("#busca_txt").val();
		else
			$("#busca_txt").focus();
	});
});