"Use of unassigned local variable" error with an Interface
===

I'm having trouble with some syntax. I'm not really familiar with interfaces so please excuse my ignorance.

VS2010 is giving me an error at... `application.Name = System.AppDomain.CurrentDomain.FriendlyName;`

	public static void AddApplication(string applicationName = null, string processImageFileName = null)
	{
		INetFwAuthorizedApplications applications;
		INetFwAuthorizedApplication application;

		if(applicationName == null)
		{
			application.Name = System.AppDomain.CurrentDomain.FriendlyName;/*set the name of the application */
		}
		else
		{
			application.Name = applicationName;/*set the name of the application */
		}

		if (processImageFileName == null)
		{
			application.ProcessImageFileName = System.Reflection.Assembly.GetExecutingAssembly().Location; /* set this property to the location of the executable file of the application*/
		}
		else
		{
			application.ProcessImageFileName = processImageFileName; /* set this property to the location of the executable file of the application*/
		}

		application.Enabled =  true; //enable it

		/*now add this application to AuthorizedApplications collection */
		Type NetFwMgrType = Type.GetTypeFromProgID("HNetCfg.FwMgr", false); 
		INetFwMgr mgr = (INetFwMgr)Activator.CreateInstance(NetFwMgrType); 
		applications = (INetFwAuthorizedApplications)mgr.LocalPolicy.CurrentProfile.AuthorizedApplications;
		applications.Add(application);
	}

I can make that error go away by setting `application` to `null` but that causes a run-time null reference error.