$(document).ready(function() {
    $("#header .siteSearch label").addClass("overlabel");
    $("label.overlabel").overlabel();
});


jQuery.fn.overlabel = function() {
    this.each(function(index) {
        var label = $(this); var field;
        var id = this.htmlFor || label.attr('for');
        if (id && (field = document.getElementById(id))) {
            var control = $(field);
            label.addClass("overlabel-apply");
            if (field.value !== '') {
                label.css("text-indent", "-1000px");
            }
            control.focus(function () {label.css("text-indent", "-1000px");}).blur(function () {
                if (this.value === '') {
                    label.css("text-indent", "0px");
                }
            });
            label.click(function() {
                var label = $(this); var field;
                var id = this.htmlFor || label.attr('for');
                if (id && (field = document.getElementById(id))) {
                    field.focus();
                }
            });
        }
    });
};

$(document).ready(function() {
    $("label.overlabel").overlabel();
});


jQuery.fn.overlabel = function() {
    this.each(function(index) {
        var label = $(this); var field;
        var id = this.htmlFor || label.attr('for');
        if (id && (field = document.getElementById(id))) {
            var control = $(field);
            label.addClass("overlabel-apply");
            if (field.value !== '') {
                label.css("text-indent", "-1000px");
            }
            control.focus(function () {label.css("text-indent", "-1000px");}).blur(function () {
                if (this.value === '') {
                    label.css("text-indent", "0px");
                }
            });
            label.click(function() {
                var label = $(this); var field;
                var id = this.htmlFor || label.attr('for');
                if (id && (field = document.getElementById(id))) {
                    field.focus();
                }
            });
        }
    });
};

http://scott.sauyet.com/thoughts/archives/2007/03/31/overlabel-with-jquery/

1. Use absolute positioning to place label over the text box
2. Hide label except when JS is enabled
3. Use jQuery to hide label when field receives focus

Overlabel technique

form, css, jquery

jQuery