LAS VEGAS -- Michelle Obama got a night out in Vegas for her 44th birthday Thursday.

It came at a cost, though -- two long days of campaigning for her husband ahead of Nevada's presidential caucuses Saturday.

"I want to publicly proclaim my love and admiration for my wife, Michelle," Democratic hopeful Barack Obama said after she introduced him to a crowd of voters at Rancho High School, who sang "Happy Birthday" to her. He joked that it was only her 29th birthday.

"Even though I'm campaigning, ladies, I just want you to know, I'm taking her out to dinner tonight," Obama said.

Advisers declined to say where they would eat, except to say it would just be the two of them.