thorw new

1. try  
2.            {  
3.                if (TextBox2.Text!= TextBox3.Text )  
4.                    throw new Exception("1");  
5.            }  
6.            catch (System.Exception ex)  
7.            {  
8.                if (ex.Message.ToString() ==("1"))  
9.                {  
10.                    errorlogin.Text = "输入的密码和确认密码不同请重新输入";  
11.                }  
12.                else  
13.                {  
14.                    MessageBox.Show(ex.ToString());  
15.                }  
16.            }