top_button=new Image(102,38); top_button2=new Image(102,38); 
top_button.src="images/top_button1.gif"; top_button2.src="images/top_button2.gif"; 
directions_button=new Image(102,38); directions_button2=new Image(102,38); 
directions_button.src="images/directions_button1.gif"; directions_button2.src="images/directions_button2.gif"; 
return_button1=new Image(102,38); return_button2=new Image(102,38); 
return_button1.src="images/return1.gif"; return_button2.src="images/return2.gif"; 
function imgover(imgname){
imgname.src = "images/arrow.gif"
}
function imgout(imgname){
imgname.src = "images/blank.gif"
}