Не срабатывает onclick на прозрачный блок

			     <div = id ='video_left_block_1'><a href="#window"> 
				     <div id = 'video_block_over' onclick = 'videoWindow($row[0])'> <img src = 'images/play_4.png'  width = '20%' heigh = 'auto'  class = 'vid_button_2'> </div> 
				     <video width="100%" height="auto"  >				  
                     <source src='video/$row[1]'>				  
                     </video> 
                 </a>					  
				 </div>