(CNN) -- Christine Levinson went to the United Nations on Monday to ask questions about her husband, Bob, a former FBI agent who vanished in Iran last year.

Christine Levinson has sought help from Zalmay Khalilzad, the U.S. ambassador to the United Nations.

Levinson flew to New York with three of her seven children in hopes of meeting the one man she hoped could really get things moving -- Iranian President Mahmoud Ahmadinejad, who is at the United Nations for a speech he is scheduled to deliver Tuesday afternoon.

Ahmadinejad declined to meet with her.

"I'm disappointed," she says.

Levinson did meet, however, with the Zalmay Khalilzad, the U.S. ambassador to the United Nations.

"He said he would do whatever he could to help me," she told CNN.

Levinson went to the United Nations with her children -- Susan, 31, Sarah, 28, and Douglas, 14. Her husband disappeared in March 2007 while on a business trip to the Iranian island of Kish.

Bob Levinson is a retired FBI agent from Coral Springs, Florida. After leaving the agency, his wife says, he worked as a security consultant specializing in cigarette smuggling.

Over the last year and half, Levinson says she has done everything she can to draw attention to her husband's disappearance.

She has given interviews, met with U.S. State Department officials, set up a Web site -- www.helpboblevinson.com -- and staged a rally. She even has offered a $5,000 reward, aimed primarily at Iranians who might have information about her husband.

Has it yielded any tips?

"No," Christine Levinson says. "Nothing."

Last year, she traveled to Iran to try to retrace her husband's steps. Back then, Iranian officials told her they would investigate and report back to her.

She says she hasn't heard a word.

"They told me when they have some information, they will let me know and in the meantime will continue to search for Bob," Levinson told CNN.

She has denied that her husband was doing business for the US government when he went missing -- she says she didn't believe so because he's a private citizen. And the State Department and FBI have denied he was working for government.

The State Department has demanded Iran free Levinson -- if it is holding him.

Levinson says her husband suffers from diabetes and high blood pressure.

She insists she is confident her husband is all right because "I haven't heard anything bad."

At times, she listens to his voicemail message, just to hear his voice.

"I still firmly believe he is alive," she says. "Every day, I tell my children to take things one day at a time.

"I just want him to know I'm still looking for him. I'll never stop looking for him."
Who has done everything to draw attention to Levinson? How much is the reward? Who said everything has been done to draw attention to the case? When did he disappear? What has been offered? What has his wife done? Does the FBI make any comments on this person? What was Levinson doing in Iran? Who disappeared in Iran in March 2007? Who disappeared in March of 2007? Amount of the reward?
Christine $5,000 Levinson March 2007 $5,000 reward, everything she can to draw attention to her husband's disappearance. FBI have denied he was working for government. security consultant Bob, Bob Levinson $5,000
question: Who has done everything to draw attention to Levinson?, answer: Christine | question: How much is the reward?, answer: $5,000 | question: Who said everything has been done to draw attention to the case?, answer: Levinson | question: When did he disappear?, answer: March 2007 | question: What has been offered?, answer: $5,000 reward, | question: What has his wife done?, answer: everything she can to draw attention to her husband's disappearance. | question: Does the FBI make any comments on this person?, answer: FBI have denied he was working for government. | question: What was Levinson doing in Iran?, answer: security consultant | question: Who disappeared in Iran in March 2007?, answer: Bob, | question: Who disappeared in March of 2007?, answer: Bob Levinson | question: Amount of the reward?, answer: $5,000