private void AddTaskBtn_Click(object sender, EventArgs e) { try { var AddProjectForm = new AddTask(SelectedProject.Project_ID); AddProjectForm.BoolRegisteredChanged += new EventHandler <BoolEvent>(AddTaskForm_BoolRegisteredChanged); AddProjectForm.ShowDialog(); AddProjectForm.BoolRegisteredChanged -= AddTaskForm_BoolRegisteredChanged; AddProjectForm.Dispose(); AddProjectForm = null; } catch (Exception) { MessageBox.Show("Failed to add project"); } }