var submitted = false;

function submitOnce() {
	if(submitted == true) { return; }
        if (document.frmSearch.cat.value=="" && document.frmSearch.loc.value=="" && document.frmSearch.bus.value=="") {
            alert("Please enter some values in the search form.");
            return false;
	}
	document.frmSearch.search.value = 'Searching Seego...';
	document.frmSearch.search.disabled = true;
	submitted = true;
}