I walked into the gym at Hempfield Area High School Friday afternoon, eagerly anticipating Barack Obama's appearance. This was my first live encounter with a presidential candidate, and I had certain expectations about the hour ahead. Some materialized, but there were surprises.

Everyone was searched before entering the school outside Greensburg. The Secret Service men were quite intimidating, standing 9 feet tall it seemed. They did not smile.

Upon entering, to my right, was a battalion of TV reporters, speaking to the cameras while illuminated by blinding stage lights. Newspaper reporters sat to the left, furiously typing on laptops. It was a half-hour before the Democratic senator from Illinois would appear.

Audience members buzzed with excitement as they took their seats in the bleachers and on chairs situated around a platform bordered in blue, and where Sen. Obama would address an estimated 2,000 people. Behind the black-draped podium, a huge banner emblazoned with Obama's slogan, "Change America Can Believe In," set the patriotic mood for the night.

As I took my place among the typing reporters, an announcer stepped to the podium and spoke into the microphone, silencing the anxious crowd. He went on to introduce a local politician, which drew polite applause.

Then Bob Casey, U.S. senator from Pennsylvania, stepped forward and repeated the endorsement he had given to Sen. Obama at Soldiers & Sailors Hall in Oakland that morning. The audience applauded enthusiastically, then erupted when Sen. Casey introduced the "guest of honor." The chant, "We want change," reverberated around the spacious gym.

Sen. Obama eventually calmed his supporters, then spoke. During his speech, I observed the spectators. Some were highly enthusiastic, nodding at every political statement. Some took pictures feverishly, listening little to what was being said. Some sat quietly, looking scholarly.

The highlight of the speech was Sen. Obama's desire to end the war quickly.

The audience roared its approval. A short while later, in town hall format, he took questions from the audience, addressing everything from taxes to immigration. Each response triggered another outburst of approval.

As he ended his speech with an enthusiastic "God Bless America!" news crews once again rushed to their cameras and microphones, the audience rushed to the center of the gym and the newspaper reporters kept on typing, which surprised me.

Music blared from the speakers and the Illinois senator stood a few feet away, grinning with the encouragement of his constituents.

It was an unforgettable experience for a 10th-grader.