jquery.defaultValue.js

(function ($) {
    $.fn.defaultValue = function (defaultValue) {
        return this.each(function (i) {
            var currentField = $(this);
            
            // Only apply the default value to text, password or textareas.
            if (currentField.is(':not(input:text)') && 
                currentField.is(':not(input:password)') && 
                currentField.is(':not(textarea)')) {
                return;
            }
            
            // Set the initial value if none is specified.
            if (currentField.val() === '' || currentField.val() === defaultValue) {
                currentField.val(defaultValue);
                currentField.addClass('default');
            } else {
                return;
            }
            
            // Set the value to blank on focus.
            currentField.bind('focus', function (event) {
                if (currentField.val() === defaultValue) {
                    currentField.val('');
                    currentField.removeClass('default');
                }
            });
            
            // Return the value to default on blur.
            currentField.bind('blur', function (event) {
                if (currentField.val() === '' || currentField.val() === defaultValue) {
                    currentField.val(defaultValue);
                    currentField.addClass('default');
                }
            });
            
            // If the field is still the default value on submit, set it to blank.
            currentField.closest('form').bind('submit', function (event) {
                if (currentField.val() === defaultValue) {
                    currentField.val('');
                    currentField.removeClass('default');
                }
            });
        });
    };
})(jQuery);