Why doesn't the text disappear?

wat is wrong wif this coding?
when the page is loaded, it is the text(mns) is suppose to be invincible until i mousover the grapic., but y once the page is loaded, all the text will appear at once, n i have 2 mouse over the graphic to make it work properly…

the script:

on (rollout)
{
mns._visible = false;
mns1._visible = false;
}
on (rollOver)
{
mns._visible = true;
mns1._visible = true;
}