function DropDown(o)
{
  var instance = this;
  instance.ParentNav = o.ParentNav;
  instance.SubNav = o.SubNav;
  instance.counter=0;
  instance.maxCounter = o.maxCounter;
  instance.duration = o.duration;
  instance.intervalID = null;
  var closePrev = null ;
  
  instance.openMenu = function()
  					  {
						 
						instance.SubNav.stop(true, true).fadeIn(600);  
					
					  };
					  
   instance.closeMenu = function()
   						{

						instance.SubNav.stop(true, true).fadeOut(600);  	
						};
						
  instance.clock = function()
  					{
					  if(instance.maxCounter>instance.counter)
					  {
						 instance.counter++; 
					  }
					  else
					  {
						 instance.stopTimer();
						 instance.closeMenu();
					  }
					};
					
  instance.startTimer = function()
  						{
							instance.intervalID = setInterval(instance.clock,instance.duration);
						};
						
  instance.stopTimer = function()
  						{
							instance.resetTimer();
							clearInterval(instance.intervalID);
						};	
						
  instance.resetTimer = function()
  						{
							instance.counter=0;
						};	
						
  instance.ParentNav.bind('mouseover',function(){
											   
														if(closePrev != null)
														{
															closePrev.hide();
															closePrev = null;
														}
																instance.stopTimer();
																instance.openMenu();
											
											
											
											
										 
										 });
  
  instance.ParentNav.bind('mouseleave',function(){
													closePrev = instance.SubNav ;
													instance.resetTimer();
													instance.startTimer();
											
											
											});
  
  
  
  instance.SubNav.bind('mouseover',function(){
												 
												  instance.stopTimer();
												  
												  });
  
  instance.SubNav.bind('mouseleave',function(){
												  
												  instance.resetTimer();
											      instance.startTimer();
												  
												  });
						
}