How do you flush the search bar

I'd like to have a text ie: search written inside the search field and I would like this text to disapear when the search field gets the focus.

I tried this code but it does'nt work even with other events like click any ideas?

mySearch.addEventListener('focus', function(e)
{
    e.value=' ';
 
});

I finally solved that by myself here's how the event argument is useless

mySearch.addEventListener('focus', function(e)
{
    mySearch.value=' ';
 
});