WASHINGTON: Signaling that she was no push-over, Alaska Governor Sarah Palin in her maiden speech at the Presidential nomination party Convention launched a scathing attack on her critics telling them she was "ready and prepared" for a fight.

Rocketed in less than a week from being an unknown politician in Alaska to the first woman Republican vice presidential candidate, Palin took on Democratic Presidential candidate Barack Obama, accusing him of using "change" to promote his career. Referring to the Convention theme of 'country first', the former beauty queen lambasted the Democratic nominee Obama as a candidate out for himself.

"Here's how I look at the choice Americans face in this election. In politics, there are some candidates who use change to promote their careers," she said. "And there are those like John McCain, who use their careers to promote change," she added.

The Republicans greeted their number two slot candidate with a thunderous and extended applause as she strode to the stage for her first speech in which she said that she had accepted the nomination to serve the American people and not to win good opinion of her detractors.

The 44-year old hockey mom of five children -- nicknamed Barracuda for her fighting spirit-- hammered away at different times at Senator Obama and his running mate Senator Joseph Biden for their policies and lack of executive experience.