TextBox Server Control
The TextBox Server Control is the control that allow users to submit their information or input text.You can use TextBox control to three different HTML elements in your forms.
First, the TextBox control can be used as a standard HTML textbox.
<asp:TextBox ID=”TextBox1″ runat=”server”></asp:TextBox>
Second, the TextBox control can allow you to input text into a form.
This is done by changing the TextMode attribute of the TextBox control to Password.
Third, the TextBox server control can be used as a multiline textbox.
<asp:TextBox ID=”TextBox1″ runat=”server” TextMode=”MultiLine” Width=”300px” Height=”150px”></asp:TextBox>
You can made changes in TextBox according to your requirement, just click the textbox placed on the design view and the property window in respect to TextBox will automatically open from where you can change its properties .such as if you want that a textbox will take input as a password then go to the TextMode property of textbox and select password. You will see many more options over there which you can change according to your Requirement.