Washington, Sep 23 : Democratic presidential candidate Barack Obama’s running mate Joe Biden has said that a campaign ad that mocked Republican presidential candidate John McCain as computer illiterate was “terrible” and would not have been done had he known about it.

Obama, McCain’s Democratic rival, launched the ad earlier this month, part of an aggressive push to slow McCain’s rise in the polls after he chose Alaska Governor Sarah Palin to be his running mate.

The ad included unflattering footage of McCain at a hearing in the early ''80s, wearing giant glasses and an out-of-style suit, interspersed with shots of a disco ball, a clunky phone, an outdated computer and a Rubik’s Cube.

“He admits he still doesn’t know how to use a computer, can’t send an e-mail, still doesn’t understand the economy, and favors 200 billion pounds in new tax cuts for corporations, but almost nothing for the middle class,” the ad says.

Asked about the negative tone of the campaign, and this ad in particular, during an interview broadcast on Monday by the CBS Evening News, Joe Biden said he disapproved of it.

“I thought that was terrible, by the way,” Biden said.

Asked why it was done, he said: “I didn''t know we did it and if I had anything to do with it, we’d have never done it.” (ANI)