$(document).ready(function() {
     var search_form = $("form.search");
     var search = $("form.search .search");
     var search_default = "Search this site...";

     search.attr("value", search_default);
     search.focus(function(){  
        if($(this).attr("value") == search_default) {
            $(this).attr("value", "");
        }
     });

     search.blur(function(){  
        if($(this).attr("value") == "") {
            $(this).attr("value", search_default);  
            $(this).removeClass("full");
        }
        else {
            $(this).addClass("full");
        }
     });

     search_form.submit(function() {
        search_box = $(this).find("input.search");
        if(search_box.attr("value") == search_default) {
            search_box.attr("value", "");
        }
     });
 });