but = new Array(6); 
buth = new Array(6); 
for (var i = 0; i < 6; i++) 
  {  
    but[i] = new Image();  
    buth[i] = new Image();    
    but[i].src = "./res/but" + (i + 1) + ".gif";  
    buth[i].src = "./res/but" + (i + 1) + "h.gif"; 
  }