It's a pale green check, number 3421, drawn on the Beverly Hills office of the Bank of America. It has been filled out with a black felt-tip pen. It's dated Feb. 1, 1982.

The payee is "Eastern High School" to the tune of $250.

The signature: Ronald Reagan.

That's right. The president of the United States read my column of last week, and out came the family checkbook. Reagan contributed 250 of his personal dollars to the kitty we're trying to put together to send the 85 members of Eastern High School's three bands to the Central Florida Fair Festival in Orlando early next month.

What's your reaction, Eastern principal Dennis Jackson?

"I'm in awe," Jackson said.

And your reaction, Anita Nance, Eastern biology teacher and unofficial spirit chairman for the bands?

"I'm so happy I could burst," Nance said.

But I have to repeat to you readers what I told Jackson and Nance.

Don't tell me about awe yet.

And don't burst with a case of the happies yet.

We've got a long way to go. And a short time to get there.

Specifically, we still lack about $11,000 of the $17,500 it will cost to send the 85 Eastern musicians to Orlando. As I write this, readers have contributed just under $3,000. But the balance must be in my hands by Feb. 26 to assure that two buses bearing the band members depart for the fair.

Looking for a reason to give? Perhaps Edward Dunton of Bethesda will stir some old fires.

"Fifty-two years ago this spring," he writes, "it was my good fortune to be a member of the Mason City, Iowa, High School Band. Having won the state high school band contest, we were eligible for the national contest to be held in Flint, Mich.

"How that small town managed on the verge of the Great Depression to raise enough money to send the 109 of us plus chaperones by Pullman to Flint, I don't know.

"But somehow the town managed. Not only was the experience itself unforgettable, but the many hours we spent practicing . . . resulted in good music becoming an important part of my life forever.

"I am happy to help pass along the favor I enjoyed."

Dunton has it exactly right. It's not a freebie we're trying to give the 85 kids from Eastern. It's an experience that they will remember all their lives, and will never have without our help.

"So why don't they help themselves?" a number of readers have asked. Why can't they do odd jobs? Or shovel snow? Or arrange to hold a fund-raising concert in the mall of a shopping center?

"Give them an opportunity to earn their trip," writes R. N. Roberts of Northwest, for example. "Look around Washington and see what giving does to the people who get and have quit trying."

But the Eastern kids have done nothing but try. They've been raising funds by selling candy since the fall. They only sought the public's help because a few cents profit on each bag of M&M's wasn't going to raise enough money in time.

Odd jobs? Dream on, Mr. Roberts. They're close to nonexistent in the neighborhoods where Eastern students live.

Get paid for shoveling snow? By whom? Families that are struggling to pay the rent?

And it's fine to say, "Go hold a concert in a shopping center." But there aren't any major ones within five miles of the school. Besides, how would the Eastern kids get to a mall in the suburbs? They can hardly tote tubas on the bus. And if they could afford cars, they'd be able to afford the $206 per person it will cost to go to Orlando.

I'm afraid it's up to you and me.

President Reagan obviously understands that, and none of us involved in this effort can thank him enough. Please follow his lead. Make your checks payable to "Eastern High School" and mail them to Bob Levey, The Washington Post, Washington, D.C., 20071.

It will be sad, indeed, if the Eastern bands don't get to go to Orlando. The only thing sadder will be if hundreds of donations have to be returned because we only get close to the total we need.