function setFocus()
{
    var txt = document.getElementById("q");
    if (txt != null)
        txt.focus();
}

function invertLanguages()
{
    var cb1 = document.getElementById("lf");
    var cb2 = document.getElementById("lt");

    c1 = cb1.value;
    c2 = cb2.value;
    
    cb1.value = c2;
    cb2.value = c1;
    
    setFocus();
}