Clear Default for input text fields using prototype 1.7.0

clear_default.js

/*
 * Clear Default Text: functions for clearing and replacing default text in
 * <input> elements.
 *
 * by Ross Shannon, http://www.yourhtmlsource.com/
 * Migrated to prototype 1.7.0 by @fjguzman
 */

document.observe("dom:loaded", function() {
    function clearDefaultText(e) {
        if (this.getValue() == this.retrieve('defaultText'))
            this.writeAttribute('value', "")
    }

    function replaceDefaultText(e) {
        if (this.getValue() == '' && this.retrieve('defaultText'))
            this.writeAttribute('value', this.retrieve('defaultText'))
    }

    $$("input[type='text']").each(function(input, index) {
        if(!input.hasClassName('cleardefault'))
          return;

        input.observe('focus', clearDefaultText).observe('blur', replaceDefaultText);

        /* Save the current value */
        if (input.getValue() != '')
            input.store('defaultText', input.getValue())
    });
});