Maintaining state for logged Users

1.    Application.Lock();  
2.           
3.         int clickCounter = 0;  
4.         if(Application["ClickCounter"] !=null)  
5.         {  
6.             clickCounter = (int)Application["ClickCounter"];  
7.         }  
8.         clickCounter++;  
9.         Application["ClickCounter"] = clickCounter;  
10.         Application.UnLock();  
11.   
12.         Label1.Text = "Button Clicked: " + clickCounter.ToString() + " times";