Why buttons are less clickable in customize callout bubble for annotationview?

Here I have pasted link for code: http://blog.asolutions.com/2010/09/building-custom-map-annotation-callouts-part-1/ In this code I have just added one simple button.but my button 开发者_StackOverflowis hardly press. we have to press long time for its click event.Not sure why buttons are less clickable? Any help will be appreciated.

Check your button bounds. They may be smaller then the frame.