Click here to watch "Zero."

Within 24 hours of the first presidential debate, both candidates were out with ads attacking the other on the topic they consider themselves more qualified in -- Barack Obama on the economy and John McCain on foreign policy.

The Obama campaign on Saturday morning released "Zero" (subscription), a spot that calls out McCain for not referencing the middle class a single time in the 90-minute forum. "McCain doesn’t get it. Barack Obama does," the announcer proclaims before the ad cuts to footage from the debate. "The fundamentals of the economy have to be measured by whether or not the middle class is getting a fair shake," Obama insists in one clip, while in another he ties McCain's tax plan to the economic policies of the current administration.

McCain was quick out of the gate with an ad of his own. "Promise" (subscription), released Saturday, pits the Democratic ticket against itself, contrasting Obama's vote against a bill to fund troops in Iraq and Afghanistan with statements Joe Biden made during the primary campaign criticizing that position.

"In the midst of war, Senator Obama voted to cut off funding for our troops," an announcer says. The ad then reruns comments Biden made jabbing his primary opponents for voting nay on the measure: "They said they voted against the money to make a political point," Biden said at an Iowa State Fair during the summer of 2007. The ad goes on to charge Obama with "playing politics" and "risking lives," by not supporting the bill.

The Obama camp was quick to respond, releasing a statement calling the McCain campaign "increasingly desperate and dishonorable." "If John McCain wants to talk about funding, he should explain why he voted against life-saving equipment for our troops in battle, voted repeatedly against funding for veterans health care and wants to keep spending $10 billion a month in Iraq while the Iraqis have a surplus and our economy is in crisis," it went on.

Unlike Obama's spot, the ad from the McCain campaign doesn't include any actual footage from the debate, but it plays indirectly off a portion of that encounter where McCain and Obama sparred over military funding. "Senator Obama, who after promising not to vote to cut off funds for the troops, did the incredible thing of voting to cut off the funds for the troops in Iraq and Afghanistan," McCain said Friday night. (McCain has made the point before, in an ad in July blasting Obama for not visiting American soldiers in Germany.)

The McCain camp did make use of clips from Friday night in a Web ad, "McCain Is Right," that was sent out later that night. The video strings together footage of the Illinois senator apparently agreeing with his opponent, calling McCain "absolutely right" time and time again. The ad concludes that Obama isn't "ready to lead." By the end of the night, Obama had indeed called McCain "absolutely right" no fewer than six times. But what the ad omits is the qualifying statements Obama amended each time he agreed with his opponent.

Mary Gilbert contributed reporting to this post.