--- loncom/interface/lonsearchcat.pm	2001/03/15 19:38:49	1.31
+++ loncom/interface/lonsearchcat.pm	2001/03/15 19:47:37	1.32
@@ -424,6 +424,20 @@ sub advancedsearch {
     my ($r,$envhash)=@_;
     my %ENV=%{$envhash};
 
+    my $fillflag=0;
+    for my $field ('title','author','subject','keywords','url','version',
+		   'notes','abstract','mime','language','owner',
+		   'custommetadata') {
+	if (&filled($ENV{'form.basicexp'})) {
+	    $fillflag++;
+	}
+    }
+
+    unless ($fillflag) {
+	&output_blank_field_error($r);
+	return OK;
+    }
+
     $r->print(<<END);
 Advanced searching is not yet implemented.
 END