myGifCnt = 14;             
myGifTbl = new Array(     
   "top_1.gif",
   "top_2.gif",
   "news_1.gif",
   "news_2.gif",
   "intro_1.gif",
   "intro_2.gif",
   "story_1.gif",
   "story_2.gif",
   "produ_1.gif",
   "produ_2.gif",
   "cast_1.gif",
   "cast_2.gif",
   "trth_1.gif",
   "trth_2.gif"
);



mySrcTbl = new Array( myGifCnt ); 
for (i=0; i<myGifCnt; i++){       
   mySrcTbl[i] = new Image();     
   mySrcTbl[i].src = myGifTbl[i]; 
}

function myChange( myBtnNo , myTblNo ){  
	document.images["myBtn"+myBtnNo].src = mySrcTbl[myTblNo].src;
}