function image_preloader(){
  i=1; imax=6*2;
  img = new Array();
  
  for(i=1;i<imax;i+=2){
  img[i] = new Image();
  img[i].src = "images/menu0"+i+"up.gif";
  img[i+1] = new Image();
  img[i+1].src = "images/menu0"+i+"on.gif";
  }
  
 }