function buscar() {
	if (document.getElementById("txtBuscar").value == '')
	{
		alert("Ingrese texto");
		document.getElementById("txtBuscar").focus();
	} 
	else
	{
		url = 'buscar.php?q=' + document.getElementById("txtBuscar").value;
		window.location = url;
	}
}

function verificarEnter() {
	if (window.event.keyCode == 13) { 
		buscar();
	};
}