private void funlimpiar()
{
cmbaerolinea.Text = "";
cmbaeropuerto.Text = "";
cmbdestino.Text = "";
cmbembarque.Text="";
cmborigen.Text = "";
cmbterminal.Text = "";
cmbtipoVuelo.Text = "";
txtBuscar.Text = "";
mtxhoraDespegue.Text="";
mtxhoraLlegada.Text="";
}