Remote patrol

If you're one of those who turned off "ER" a couple of seasons back, tonight's repeat from last fall is worth a look: It's the start of a multi-episode arc in which Alan Alda plays a hotshot doctor brought over from another hospital in town. The other medics are put off by his breezy manner; what they'll soon realize is that the swagger is a bit of a front. The old pro is losing not only his touch but also his battle with a degenerative disease. Rebecca DeMornay also guest-stars. Speaking of high-quality repeats, the hilarious two-part "Friends" from London that wrapped up the 1997-98 season airs at 10:30 p.m. today and Friday on Channel 4. @ART CAPTION:Alda @ART:Photo (color)