if (document.images) 
{  
img01 = new Image ;
img02 = new Image ;
img03 = new Image ;
img04 = new Image ;
img05 = new Image ;
  
img01.src = "i/buttons/but010o.gif";
img02.src = "i/buttons/but020o.gif";
img03.src = "i/buttons/but030o.gif";
img04.src = "i/buttons/but040o.gif"; 
img05.src = "i/buttons/but050o.gif";

}