ASP.NET Primer

In this column, we introduce you to a whole new world, ASP.NET. In much the same way that JavaScript goes hand in hand with HTML, JScript .NET goes hand in hand with ASP.NET. The difference between these two pairs is that one pair (HTML and JavaScript) works on the client side (your PC), while the other pair (ASP.NET and JScript .NET) works on the server side (your IIS Web server). The advantage of JavaScript and JScript .NET over other scripting languages is that you can use the same language on both the client and the server. JScript. NET is indeed extended JavaScript, but we suspect the development of JScript .NET, JavaScript, and ECMAScript will become even more similar as time goes by.

ASP.NET (Active Server Pages) is one of the alternatives to interact with a server. Other competitors are JSP (Java Server Pages) which is popular on Unix, and PHP which is open source software. ASP.NET also supports both the Visual Basic and C# scripting languages. To learn more on ASP.NET go here. In this column, we'll teach you just enough to understand what's going on, who is calling whom, and how data is passed around.

The syntax of ASP.NET is very similar to HTML. It is based on tags, also called controls. Each tag has its own parameters which control its appearance and behavior. You can mix ASP.NET and HTML tags. The ASP.NET tags run on the server, while the HTML tags run on the client. The information displayed by the browser is regular HTML; so you don't know exactly, just by looking at the browser, what is running where. The ASP.NET tags have two parameters in common: RUNAT="server" and ID. The ID parameter is used for event handlers and other references.

Here is the list of ASP.NET tags (controls):

• asp:Button
• asp:Label
• asp:Literal
• asp:TextBox
• asp:CheckBox
• asp:RadioButton
• asp:RadioButtonList
• asp:DropDownList
• asp:ListBox
• asp:Button
• asp:LinkButton
• asp:ImageButton
• asp:Image
• asp:AdRotator
• asp:Panel
• asp:PlaceHolder
• asp:Table
• asp:Calendar
• asp:DataGrid
• asp:DataList
• asp:RegularExpressionValidator
• asp:RequiredFieldValidator
• asp:CompareValidator
• asp:RangeValidator
• asp:CustomValidator
• asp:ValidationSummary
• asp:Xml

In this column, we will use just two of the above: asp:Button and asp:TextBox. Usually, you will use these controls inside a FORM tag which includes the directive RUNAT="server". This form is also known as the ASP.NET Web form, as opposed to the ASP.NET Windows form, used in Windows-based applications. As in HTML, ASP.NET is case insensitive.