(AP) - Republican vice presidential candidate SarahPalin accused Barack Obama of voting against funding for U.S.troops in combat Thursday night in her much-anticipated debate withObama's running mate, Joe Biden, whom she chastised for defendingthe move, "especially with your son in the National Guard" andheaded for Iraq.

"John McCain voted against funding for the troops," as well,Biden countered, adding that the Republican presidential candidatehad been "dead wrong on the fundamental issues relating to theconduct of the war."

Biden did not immediately reply to Palin's mention of his son,Beau, the Delaware attorney general, who is scheduled to fly toIraq with his National Guard soon.

Palin has a young son who is in Iraq with the Alaska NationalGuard, although she did not refer to it.

The exchange over Iraq was easily the most personal, and amongthe most pointed, as the two running mates debated across 90minutes on a stage at Washington University.

They also clashed over energy, the economy, global warming andmore in their only debate, with little more than one monthremaining in the campaign and McCain struggling to regain hisfooting.

Republican officials disclosed earlier in the day that he wasconceding the battleground state of Michigan to Obama. The statevoted Democratic four years ago, but McCain had spent millionstrying to place it in his column.

Biden was scathing in his criticism of McCain's position on theIraq war, calling him the "odd man out" for his refusal to accepta timeline for the withdrawal of U.S. troops.

But Palin countered that a timetable was tantamount to "a whiteflag of surrender in Iraq," and at a moment when victory was"within sight."

She also said Biden had once supported McCain's view of the war,and noted that he had once said of Obama that he wasn't ready to becommander in chief ... "and I know again that you opposed the movethat he made to try to cut off funding for the troops and I respectyou for that."

"I don't know how you can defend that position now but - I knowthat you know, especially with your son in the National Guard."

As for Obama, she said, "Another story there. Anyone I thinkwho can cut off funding for the troops after promising not to -that's another story."

Biden's reply was in clipped tones. "John McCain voted to cutoff funding for the troops. Let me say that again. John McCainvoted against an amendment containing $1 billion, 600 milliondollars" for protective equipment that is "protecting thegovernor's son and, pray God, my son and a lot of other sons anddaughters. He voted against it."

Palin, who has been governor of her state less than two years,was under intense pressure to demonstrate a strong grasp of theissues as she stepped onto the stage. Polls show the public hasbecome increasingly skeptical of her readiness for high publicoffice.

As is her custom on the campaign, she spoke in familiar terms,saying "betcha" rather than "bet you" and "gonna" rather than"going to."

She also spoke to the home folks. "Here's a shout-out" tothird graders at Gladys Wood Elementary School in Alaska. She saidthey would all receive extra credit for watching the debate.

"Can I call you Joe?" she asked Biden as they shook handsbefore taking their places behind identical lecterns.

He readily agreed she could - and she used it to effect morethan an hour later. "Say it ain't so, Joe," she said as shesmilingly criticized him at one point for focusing his comments onthe Bush administration rather than the future.

She made only one obvious stumble, when she twice referred tothe top U.S. general in Afghanistan as "Gen. McClellan." In fact,his name is David McKiernan.

Biden's burden was not nearly as fundamental. Although he haslong had a reputation for long-windedness, he is a veteran of morethan 35 years in the Senate, with a strong knowledge of foreignpolicy as well as domestic issues.

For much of the evening, the debate unfolded in traditional vicepresidential fashion - the running mates praising their ownpresidential candidate and denigrating the other.

Palin said Obama had voted to raise taxes 94 times - anallegation that Biden disputed and then countered. By the samereckoning, he said, McCain voted "477 times to raise taxes."

They clashed over energy policy, as well, when Palin saidObama's vote for a Bush administration-backed bill granted breaksto the oil industry. By contrast, she said that as governor, shehad stood up to the same industry, and noted that McCain had votedagainst the bill Obama supported.

Biden said that in the past decade, McCain had voted "20 timesagainst funding alternative energy sources and thinks, I guess, theonly answer is drill, drill, drill."

"The chant is, `drill, baby drill," Palin countered quickly,unwilling to yield to Biden on that issue - or any other.

On the environment, Palin declined to attribute the cause ofclimate change to man-made activities alone. "There is somethingto be said also for man's activities, but also for the cyclicaltemperature changes on our planet," she said, adding that shedidn't want to argue about the causes.

Biden said the cause was clearly man-made, and added, "If youdon't understand what the cause is, it's virtually impossible tocome up with a solution."