resolved bug: crash if waitbar was called with '0'

waitbar.m

@@ -82,7 +82,12 @@ switch type
   lastUpdate = get(f,'UserData');
   dx = x;
   dt = etime(clock,lastUpdate.time);
-  secRemain = dt/dx * (100 - x);
+  if dx > 0
+      secRemain = dt/dx * (100 - x);
+  else
+      secRemain = 0;
+  end
+  
   timeRemain = [];
   if (secRemain > lastUpdate.showTime | lastUpdate.flag) & lastUpdate.showTime >= 0
       tx = datestr(datenum(0, 0, 0, 0, 0, secRemain),13);