How to: Set ASP.NET Server Control Properties
Setting a control's properties defines its appearance and behavior. This topic addresses how to set control properties at design time using Visual Web Developer.
To set server controls properties in the designer
In Design view, select the control, and then set properties in the Properties window.
In Source view, place the insertion point in the element tag of the control, and then set properties in the Properties window.
To set server controls properties using ASP.NET syntax
Switch to Source view.
In the control's markup element, set the attribute of the control declaration corresponding to the property you want.
In Web server controls, the property names do not necessarily have the same names as HTML attributes; be sure you are using the correct property name.
<input id="SampleTextBox" type=text runat=server maxlength="20" >
<asp:textbox text="" runat=Server TextMode="Multiline" />