var nimages1 = 0,nimages2 = 0;

function SlideShow1(num)          
{
  switch (num)
  {
  case 1:if(nimages1 == 0)  break; 
         if(nimages1 == mySlideList1.length-1) 
                 document.getElementById("bat_right1").style.visibility="visible";
        nimages1--;
        if(nimages1 == 0) document.getElementById("bat_left1").style.visibility="hidden";
        switchImage("slide1", mySlideList1[nimages1],"images/");
        break;
  case 2:if(nimages1 == mySlideList1.length-1)  break;  
        if(nimages1 == 0) document.getElementById("bat_left1").style.visibility="visible";
        nimages1++;
        if(nimages1 == mySlideList1.length-1) 
                 document.getElementById("bat_right1").style.visibility="hidden";
        switchImage("slide1", mySlideList1[nimages1],"images/");
        break;
  case 3:if(nimages2 == 0)  break; 
        nimages2--;
        if(nimages2 < mySlideList1.length-1) { 
                 document.getElementById("bat_right2").style.visibility="visible";
                 switchImage("bat_right2", mySlideList1[nimages2 + 1],"images/");
        }
        if(nimages2 == 0) 
                 document.getElementById("bat_left2").style.visibility="hidden";
        else 
                 switchImage("bat_left2", mySlideList1[nimages2 - 1],"images/");
        switchImage("slide2", mySlideList1[nimages2],"images/");
        break;
  case 4:if(nimages2 == mySlideList1.length-1)  break;  
        nimages2++;
        if(nimages2 > 0) 
                 document.getElementById("bat_left2").style.visibility="visible";
        switchImage("bat_left2", mySlideList1[nimages2 - 1],"images/");
        if(nimages2 == mySlideList1.length-1)
                 document.getElementById("bat_right2").style.visibility="hidden";
        else 
                 switchImage("bat_right2", mySlideList1[nimages2 + 1],"images/");
        switchImage("slide2", mySlideList1[nimages2],"images/");
        break;
  }
}
function switchImage(imagesName,imagesSrc,put) 
{
        if (document.images) {
                 if (imagesSrc != "none")
                 document.images[imagesName].src = put + imagesSrc;
  }
}