gluon-web: empty contact/location needs user confirmation

package/gluon-web-model/files/lib/gluon/web/view/model/form.html

@@ -25,4 +25,40 @@
 		" />
 	<% end %>
 	</div>
+
+	<script type="text/javascript">
+	//<![CDATA[
+		function $ (selector, el) {
+			if (!el) {el = document;}
+			return el.querySelector(selector);
+		}
+		var inputContact = $("input[name$='contact']");
+		if (typeof(inputContact) != 'undefined' && inputContact != null) {
+			var form = $("form");
+			function isEmpty(elem) {
+				if (elem == null || elem.value == null || elem.value == "" || elem.value == "0")
+					return true
+				return false
+			}
+			form.addEventListener('submit', function formSubmit(evt) {
+				var inputLocation = $("input[name$='location']");
+				var inputLocLat = $("input[name$='latitude']");
+				var inputLocLong = $("input[name$='longitude']");
+				var confirmContact = true;
+				var confirmLocation = true;
+				if (isEmpty(inputContact))
+					confirmContact = confirm("Willst Du wirklich keine Kontaktinformation hinterlegen?");
+				if (isEmpty(inputLocation) || isEmpty(inputLocLat) || isEmpty(inputLocLong))
+					confirmLocation = confirm("Willst Du wirklich keinen Standort angeben?");
+				if (!confirmContact || !confirmLocation) {
+					evt.returnValue = false;
+					if (evt.preventDefault) evt.preventDefault();
+					return false;
+				}
+				return true;
+			}, false);
+		}
+	//]]>
+	</script>
+
 </form>