[horde] help with horde and php

[mrinal joshi]

My horde imp system was working fully till yesterday. but now one problem is arised.

I can get my mails , send my mails through turba. but when i click on links like folders or options for setting preference or mail address book, browser tell me to open / save file, it should execute it na.

everything was working absolutely fine since last 2 years, i don't know what happenned. i even tried to check for its php problem, by creating test file and executing it in browser, it got executed but when i try to open the test file of horde it again gives same meassage.
 

Please guide me.