How to make visibility instead of display?

There is a script, if you select one of the options falls review. When you select a different menu option, the comment disappears and there is a review to this option.

How to make instead

p {
 display: none; 
}

it was stated

p {
 visibility: hidden; position: absolute;
}

and when you click the specified paragraph gradually appear (and another paragraph, if activated - disappeared), he asked

p {
 visibility: visible; position: initial;
}