function formatString(items) {
         var modplus = "";
         for (var t = 1 ; t <= items.length ; t++) {
                if (items.substring(t-1,t) == " ") {
                    modplus+="+";
                } else {
                    modplus+=items.substring(t-1,t);
                }
        }
        return modplus;
}

function buildUrl() {
       	var words;
        words = document.searchform.query.value;
        var searchitems;
        // format words
        searchitems=formatString(words);
        var index;  
        index = document.searchform.usesite.selectedIndex;
        var site;
        site = document.searchform.usesite.options[index].value;
        site+=searchitems;
		// execute
		window.open(site, 'Search');
}