I have my own exception based on some condition and want to raise an alert when control comes in this catch block
catch (ApplicationException ex) { //want t
Do you mean, a message box?
MessageBox.Show("Error Message", "Error Title", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
More information here: http://msdn.microsoft.com/en-us/library/system.windows.forms.messagebox(v=VS.100).aspx