visual studio doesn't tell me when i type a control that doesn't exist

I noticed that VS2008 doesn开发者_如何转开发't tell me when I'm typing a control name that doesn't exist. why is that?

yes, the problem was that I didn't have SP1 installed

Have you switched it off accidentally?

In the options dialog select the Text Editor node, then C# (or whatever language you are using) and go to the Advanced node. Ensure that 'Show live semantic errors' is ticked:

More info: http://ira.me.uk/2008/09/01/switch-offon-visual-studio-2008-background-compilation/

You didn't say which language you're using, but I expect the setting to be the same as it is for C#. Go to Tools -> Options. Then scroll the list on the left to "Text Editor". Select the language, and look in "Advanced". There's are options under "Editor Help" -- make sure "Underline errors in the editor" and "Show live semantic errors" are checked.