\nthis.txtQryCustomer.Leave += new System.EventHandler(this.test_change);\nthis.txtQryCustomer.Enter += new System.EventHandler(this.save_value);\n\nprivate string str_save_value = "";\n\n\nprivate void save_value(object sender, System.EventArgs e)\n{\n   str_save_value = ((TextBox)sender).Text;\t\t\t\n}\n\nprivate void test_change(object sender, System.EventArgs e)\n{\n  if (str_save_value != ((TextBox)sender).Text)\n  {\n    MessageBox.Show("In changed!");\n  }\n}\t\n