You could put it in a saucer and then stand that saucer in a larger saucer filled with water (this way the plant is not waterlogged). The evaporating moisture keeps the plant humid and helps alleviate the problem. Trim off any brown bits of leaf or the whole leaf if its a large patch.

It may also be in need of repotting

Drafts can also cause leaves to go brown, but if it is large as you say it could be in need of repotting/dividing.

Thanks everyone. I have re-potted it because I wanted to check if the roots had cooked. I will try the moisture idea. That makes good sense. Also I will check for drafts that may well be an issue.
cheers folks happy gardening.

You're welcome :o)

And - sadly, remeber that plants do come to the end of their planty life and need to move on to compost and being a new plant