New Carpet and Decorating - which way round?

We are possibly/probably/may/might/could be freshening up our bedroom, the walls and ceiling are just emulsion and the doors and skirting gloss. We need a new carpet. Should be have carpet fitted first then paint or tother way round? I know you lot will know and thanks in ant......although it would appear I am on the sofa for a few hours yet, comtemplating!, so no rush x