[jQuery] Using jQuery to select text
I'd like to prefill a text box in a form with a typical value, but
select the text, so that if the user begins typing, the prefilled text
is overwritten, wihtout him having to erase it. (Just like the
location bar in my browser - if I click on it, the text becomes
selected, so that one key overwrites the old location, without me
having to backspace.)
Can I do this with JQuery/JavaScript? How?
Also, is there a way to disable the submit button unless the text in
the box validates (in this case, it has to be filled out, and it has
to be numeric)?