Advance ticketsare available beginning November 19 at the PFA business office, 9 a.m. -12 noon and 1 - 5 p.m., and at the PFA box office during evening hours. An American president for Nicaragua? Perhaps theabsurdity of the notion could only be translated to film by the likes ofAlex Cox, director of Repo Man, Sid and Nancy and Straight to Hell. Butthe catch is that Walker, Cox's new film shot in Nicaragua, is a truestory. William Walker was a Tennessee-born adventurer who, with hisragtag army of "Immortals," otherwise known as"Filibusterers," came to Nicaragua in 1855 at the invitationof the liberal faction and in 1856, after a bogus election, wasinstalled as President. By the end of the next year, Walker had beenejected by an astounding coalition of all five Central American nationsand when he attempted a comeback, was executed in 1860 by a Honduranfiring squad. Walker is the story of the short reign of thisself-proclaimed potentate who was bold, cocksure and cruel; two years ofbloody tyranny in the life of Nicaragua that obviously resonate to thesituation today. "That's obvious in the thinking that you cancontrol the lives of foreign populations by sheer power," Alex Coxsaid in a recent Village Voice interview. "Walker was filled withthe spirit of democracy, Christianity, God, manifest destiny, and theidea that the United States must expand till it fills the whole of theAmerican continent." In Walker, Cox and scriptwriter Rudy Wurlitzerplay the allegory for an often surrealistic black comedy, with elementsof pirate movie and spaghetti Western thrown in (as much by thecharacter as by the interpretation). And actor Ed Harris-who hasrecreated the gamut of American types, from the hero John Glenn in TheRight Stuff to the amoral mercenary in Under Fire-plays Walker, the man,for the sincerity of his arrogance, the extreme of delusion.