function showDiv( div_id ) {
    document.getElementById( div_id ).style.display = "block";
}

function hideDiv( div_id ) {
    document.getElementById( div_id ).style.display = "none";
}

function showText( el, def_str ) {
    if( el.value.replace(/^\s+|\s+$/g, '') == "" ) {
        el.value = def_str;
    }
}

function hideText( el, def_str ) {
    if( el.value == def_str ) {
        el.value = "";
        el.focus();
    }
}