Hitting the enter key in a TextBox can sometimes have undesired effects like the wrong submit Button being “clicked“. The method described below allows you to specify a default Button to submit when the user hits the enter key in a TextBox.When you press a key on your keyboard, the js OnKeyPress event is fired. This calls a function to which we pass the id of the button associated with the TextBox. The function gets a reference to the button and simuilates a mouse-click on the Button. We perform a browser detection because IE and Netscape have different event models. The function finally returns false so that the keypress event is cancelled (otherwise a second form submit will be raised). This works with newer versions of IE/Netscape.
TextBox1.Attributes.Add("onkeypress", "return clickButton(event,'" + Button1.ClientID + "')");
<input name="TextBox1" type="text" id="TextBox1" onkeypress="return clickButton(event,'Button1')" />This causes web control Button1 to be clicked when the enter key is hit inside TextBox1.