Usually you don't need to do this again, But in case you want to re-add the widget, here's the code to copy to the HTML/Javascript widget
<div><form action="/search" id="searchthis" class="searchwrap" method="get"> <input id="search-box" name="q" onfocus="if (this.value==this.defaultValue) this.value = ''" onblur="if (this.value=='') this.value = this.defaultValue" value="Search here and enter" type="text" /></form></div>