function SwapImage1() {
  document.image1.src="images/f&l_spread_back.jpg"
}
function SwapImage1Back() {
  document.image1.src="images/f&l_spread.jpg"
}
function SwapImage2() {
  document.image2.src="images/mem_spread_back.jpg"
}
function SwapImage2Back() {
  document.image2.src="images/mem_spread.jpg"
}
function SwapImage3() {
  document.image3.src="images/door_spread_back.jpg"
}
function SwapImage3Back() {
  document.image3.src="images/door_spread.jpg"
}
function SwapImage4() {
  document.image4.src="images/sayas_spread_back.jpg"
}
function SwapImage4Back() {
  document.image4.src="images/sayas_spread.jpg"
}