function mouseLeftOver()
{
   document.getElementById("b1").src ="/clipart/buttons/left_over.png";
}
function mouseLeftDown()
{
   document.getElementById("b1").src ="/clipart/buttons/left_down.png";
}
function mouseLeftOut()
{
   document.getElementById("b1").src ="/clipart/buttons/left.png";
}
function mouseRightOver()
{
   document.getElementById("b2").src ="/clipart/buttons/right_over.png";
}
function mouseRightDown()
{
   document.getElementById("b2").src ="/clipart/buttons/right_down.png";
}
function mouseRightOut()
{
   document.getElementById("b2").src ="/clipart/buttons/right.png";
}