function GetNewImage(stoneID)
{ 
 var image = document.getElementById(stoneID);
 if (image != null)
 {
    image.src = 'images/bt_weiss_bg.gif';
 }
 return true; 
}
    
function GetOldImage(stoneID)
{ 
 var image = document.getElementById(stoneID);
 if (image != null)
 {
    image.src = 'images/bt_schwarz_bg.gif';
 }
 return true; 
}