[jQuery] A better way to refill form values?

[703designs]

Here's what I have right now:

$(document).ready(function() {
    $("form input:text").focus(function() {
        this.oldvalue = $(this).attr("value");
        $(this).attr("value", "");
    }).blur(function() {
        $(this).attr("value", this.oldvalue)
    })
})

But I'm sure it could be written better. Ideas? The main problem is
that focusing on an already filled field will empty it...not sure how
I'll work around that.