Virginia state Del. Alan A. Diamonstein (D-Newport News) is identified incorrectly in a photo caption in today's Virginia Weekly, which is printed in advance.

This was supposed to be "the year of the budget" in the Virginia General Assembly, a session when lawmakers from the Washington suburbs would wage regional warfare with their colleagues from across the state over which portion of the state would bear the brunt of spending cutbacks forced by a painful state revenue crunch.

But as they packed their bags Sunday afternoon, the 29 members of Northern Virginia's delegation were congratulating themselves for escaping unscathed. There were no great gains for the region during the 47-day session, but thanks to deft maneuvering by the legislature's money committees, legislators said there were no great losses either.

While that may sound like a modest accomplishment, it was enough for most Northern Virginia lawmakers to hail the so-called "short" session a smashing success.

"It's been a boring session, but boring in this case is probably good," said Del. David Brickley (D-Prince William). "We've really come out of here with our pants on."

And since all 140 of the legislature's seats are up for election this fall, many legislators said that may not be a minor achievement. The session was short on what Del. Mary A. Marshall (D-Arlington) called "the dazzle and drama" of past years when state funding of the Metro transit system was at stake.

But the unsuccessful campaign to boost Virginia's drinking age to 21 aroused the passions of several Northern Virginia groups who have vowed to try again next year. Some lawmakers speculate these groups, unhappy over the Assembly's compromise boosting the beer-drinking age to 19, may try to make the drinking age an issue in the November elections.

Alcohol was the focus of other legislation that takes effect July 1. The Assembly voted to allow state-run liquor stores to vary prices in different parts of the state, an action that should mean lower prices for Northern Virginians.

The bill, introduced by retiring State Sen. Adelard L. Brault (D-Fairfax), was aimed at helping state-run stores in the suburbs compete with privately run liquor stores in the District and Maryland which frequently sell the same brands much more cheaply.

A measure sponsored by Sen. Wiley F. Mitchell Jr. (R-Alexandria), calling for a study of a regional bus system in Northern Virginia, possibly to replace some Metro routes, also passed. Both Fairfax County and Alexandria have indicated they may establish their own bus operations rather than face the mounting costs of Metro's bus operations. Fairfax County

Fairfax County won its top legislative priority: the right to spend $55 million during any five-year period for upgrading and improving roads.

County officials had complained the state was too slow in making improvements and that the current $10 million annual limit imposed by the state would make it difficult to tackle more than one major project in a year. The county also won the right to condemn and purchase land for road projects without going to court, a power until now vested only in the state highway department.

That bill was imperiled briefly by a bitter feud between Arlington delegate Marshall and State Sen. Richard L. Saslaw (D-Fairfax). The two legislators ended their battle, but not until Fairfax senators helped kill a Marshall-sponsored bill after Marshall opposed the road bill, calling it "the great Fairfax treasury raid."

The legislature passed a bill sponsored by Del. Warren E. Barry (R-Fairfax) and heavily promoted by the Northern Virginia real estate industry that would keep county water and sewer authorities from holding landlords responsible for bills their tenants run up.

After local governments lobbied against the bill, Barry, who runs a property management firm, agreed to a compromise that would allow authorities to charge landlords for a maximum water use of 90 days. The Mount Vernon area failed to win relief for its high school basketball team, which had been placed on probation by the Virginia High School League following a recruiting scandal. Resolutions calling for a study of the sanctions were killed.

Another priority for the neighborhood, putting an "adult" bookstore out of business, had mixed success. A bill sponsored by Sen. Joseph V. Gartlan Jr. (D-Fairfax) to allow $10,000 fines to be levied against repeat offenders of the state's obscenity law was approved. Two other measures Gartlan aimed at the bookstore, which has numerous convictions under the law, were defeated.

Del. Kenneth J. Plum (D-Reston), responding to an incident at a Reston synagogue, convinced the legislature to expand a state law making it a crime to deface cemeteries or religious buildings with a swastika. Arlington County

The legislature approved a bill sought by Arlington County legislators that will permit operators of private businesses to "boot" improperly parked cars to prevent them from being driven away before a fine is paid. Loudoun, Prince William

Loudoun County won an annexation bill that allows it to settle a dispute with Leesburg, the county seat, without an expensive court battle. It also enables Manassas to settle a dispute with Prince William County avoiding a court case that could have cost $500,000.

The legislature agreed to impose new inspection standards on commuter buses in Virginia, a measure that Brickley sponsored in an attempt to prevent accidents like the 1981 crash of a commuter bus on I-95 near Quantico that killed 11. Alexandria

An Alexandria city charter bill was passed without a provision opposed by the state's gun lobby that would have allowed the city to continue its 35-year practice of doing background checks on people buying guns. Alexandria delegates said that they have been told they will receive a letter from state Attorney General Gerald L. Baliles permitting the city to continue the checks. Taxes

Although Virginia lawmakers are generally loath to increase taxes in an election year, the legislature did raise some fees. Some examples:

The cost of a marriage license will go from $7 to $10, while the cost of filing for a divorce will jump from $25 to $40.

Fees for annual auto emission inspections will be raised from $3.50 to $3.85.

Motor vehicle licenses will jump $1 under a so-called "one for life" proposal that will earmark the added money for emergency rescue squads. Bills Killed

Arlington and Prince William Counties were rebuffed in their perennial quests for approval of elected, rather than appointed, school boards.

Prince William State Sen. Charles J. Colgan withdrew his bill that would have allowed officials of a church-run home for retarded children near Charlottesville to spank the youngsters. The measure aroused a furor from civil liberties groups as it was on the verge of passage.

Concerned by the increase in rabies cases, Brickley sponsored a bill that would allow persons to shoot dogs and cats that roam on their property. The bill was killed after animal lovers, led by the Northern Virginia Humane Society argued the measure could lead to the indiscriminate slaughter of pets.

Virginia's businesses were defeated in their attempt to restore a one-week waiting period for persons collecting unemployment benefits. But bankers won a big symbolic victory when the assembly passed a bill that permits out-of-state bank holding companies to base their credit card operations in Virginia, which last year abolished the ceiling on credit card interest rates.

Black Virginians saw the defeat of several measures, chief among them an effort to make Martin Luther King's Jan. 15 birthday a state holiday. Also killed was a package of bills designed to swell Virginia's low voter registration rolls. General Legislation

Anticrime bills fared better, however. The legislature passed a bill, championed by some antidrunk driving groups, that allows preparation of a "victim impact statement" prior to sentencing of those convicted of felonies. Also passed were laws strengthening the penalties for "kiddie porn," the use of children in pornographic publications and films and a "Tylenol bill" that would make it a separate crime to adulterate food, drink or drugs.

The assembly passed the Natural Death Act which had failed five times earlier to emerge from committee. Sponsored by Del. Bernard S. Cohen (D-Alexandria) and backed by the Richmond Catholic diocese and the Virginia Medical Society, it allows terminally ill people to order that their lives not be prolonged by artificial means.

The conclusion of the session marks the departure from Richmond of two senior members of the Northern Virginia delegation--Brault, the 72-year-old retiring dean of the delegation, and Barry, one of the legislature's most senior Republicans. Brault has announced his retirement from politics while Barry, a member of the assembly for 14 years, plans to run for clerk of Fairfax County Circuit Court this fall.