If you use Dreamweaver CS2 or CS3 and code in ASP.NET you’ll know about an annoying problem it has (I’m not sure if they have fixed it for CS4) – Dreamweaver doesn’t know what a Master page is and tus treats it like plain text, meaning when you open it up you get no intelli-sense or ASP.NET support!   This is really easy to fix with a quick edit of an XML file in the install directory of Dreamweaver

1.) Open up the following folder - C:\Program Files (x86)\Adobe\Adobe Dreamweaver CS3\configuration\DocumentTypes
This is the default install directory

2.) Next open up the file MMDocumentTypes.xml

3.) Now locate around line 57 a <documenttype> entry with an id of ASP.NET_VB

All you need to do is edit the attributes winfileextension=”” & macfileextension=”” and add your master page like so

Do this for both the ASP.NET_VB & ASP.NET_CSharp entries, then save the file and close down Dreamweaver – Now open it up again and when you open a Master page you’ll see it treats it just like a ASP.NET page and you have full intellisense.