function newImage(arg) {
if (document.images) {
rslt = new Image();
rslt.src = arg;
return rslt;
}
}

function changeImages() {
if (document.images && (preloadFlag == true)) {
for (var i=0; i<changeImages.arguments.length; i+=2) {
document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
}
}
}

var preloadFlag = false;
function preloadImages() {
if (document.images) {
b_sport_over = newImage("images/b_sport_over.gif");
b_theatre_over = newImage("images/b_theatre_over.gif");
b_music_over = newImage("images/b_music_over.gif");
b_special_over = newImage("images/b_special_over.gif");
tnav_home_over = newImage("images/tnav_home-over.gif");
tnav_contact_over = newImage("images/tnav_contact-over.gif");
preloadFlag = true;
}
}

function clearText(field){

    if (field.defaultValue == field.value) field.value = '';
    else if (field.value == '') field.value = field.defaultValue;

}