As I understand it, ASP.NET is all about an integrated suite of technologies (e.g., C#, HTML, javascript, CSS, etc.) and you interact with all of them via one of microsoft's Integrated Development Environments (IDEs) such as Visual Studio. While this offers extraordinary convenience in some cases, it also isolates you from the underlying technologies. The IDE gives you convenient functions like "insert linkButton" and then handles all the details of writing some HTML, writing some Javascript, etc.
PHP is not like this. My understanding (and someone correct me if I'm wrong) is that PHP comprises a programming language called PHP and the PHP runtime which takes your PHP scripts and compiles them into byte code and then runs that code for you, either inside an apache module or perhaps from the command line.
The 'button' that you talk about is something that is displayed as HTML. It would be up to you to create a PHP script or HTML that displayed a a button and then assign some Javascript to it (or perhaps put it in a form which submits to the second page) or maybe you could just create an HTML <a> tag that looks like a button. There are a number of ways to do this, each with its own advantages and disadvantages.
You might be able to find some kind of IDE for developing PHP that offers you that kind of fully integrated convenience, but I don't know of any.
