if (document.images) {

//create "on" array and populate with image objects
   var onImgArray = new Array ()
   onImgArray[0] = new Image(142,22)
   onImgArray[1] = new Image(142,22)
   onImgArray[2] = new Image(142,22)
   onImgArray[3] = new Image(142,22)
   onImgArray[4] = new Image(90,30)
   onImgArray[5] = new Image(90,30)
   onImgArray[6] = new Image(90,30)
   onImgArray[7] = new Image(90,30)
   onImgArray[8] = new Image(90,30)
   onImgArray[9] = new Image(90,30)
   onImgArray[10] = new Image(90,30)
   onImgArray[11] = new Image(90,30)
   onImgArray[12] = new Image(90,30)
   onImgArray[13] = new Image(90,30)
   onImgArray[14] = new Image(90,30)
   onImgArray[15] = new Image(90,30)
   onImgArray[16] = new Image(90,30)

//set URLs for the "on" images
   onImgArray[0].src = "images/btn-contact-on.png"
   onImgArray[1].src = "images/btn-help-on.png"
   onImgArray[2].src = "images/btn-cart-on.png"
   onImgArray[3].src = "images/btn-products-on.png"
   onImgArray[4].src = "images/brand-icon-Unilens-on.jpg"
   onImgArray[5].src = "images/brand-icon-CooperVision-on.jpg"
   onImgArray[6].src = "images/brand-icon-SofLens-on.jpg"
   onImgArray[7].src = "images/brand-icon-Acuvue-on.jpg"
   onImgArray[8].src = "images/brand-icon-Dailies-on.jpg"
   onImgArray[9].src = "images/brand-icon-Focus-on.jpg"
   onImgArray[10].src = "images/brand-icon-Proclear-on.jpg"
   onImgArray[11].src = "images/brand-icon-Ciba-Vision-on.jpg"
   onImgArray[12].src = "images/brand-icon-FreshLook-on.jpg"
   onImgArray[13].src = "images/brand-icon-Bausch-&-Lomb-on.jpg"
   onImgArray[14].src = "images/brand-icon-Biofinity-on.jpg"
   onImgArray[15].src = "images/brand-icon-Purevision-on.jpg"
   onImgArray[16].src = "images/brand-icon-Air-Optix-on.jpg"
   
//create "off" array and populate with image objects
   var offImgArray = new Array ()
   offImgArray[0] = new Image(142,22)
   offImgArray[1] = new Image(142,22)
   offImgArray[2] = new Image(142,22)
   offImgArray[3] = new Image(142,22)
   offImgArray[4] = new Image(90,30)
   offImgArray[5] = new Image(90,30)
   offImgArray[6] = new Image(90,30)
   offImgArray[7] = new Image(90,30)
   offImgArray[8] = new Image(90,30)
   offImgArray[9] = new Image(90,30)
   offImgArray[10] = new Image(90,30)
   offImgArray[11] = new Image(90,30)
   offImgArray[12] = new Image(90,30)
   offImgArray[13] = new Image(90,30)
   offImgArray[14] = new Image(90,30)
   offImgArray[15] = new Image(90,30)
   offImgArray[16] = new Image(90,30)

//set URLs for the "off" images
   offImgArray[0].src = "images/btn-contact-off.png"
   offImgArray[1].src = "images/btn-help-off.png"
   offImgArray[2].src = "images/btn-cart-off.png"
   offImgArray[3].src = "images/btn-products-off.png"
   offImgArray[4].src = "images/brand-icon-Unilens-off.jpg"
   offImgArray[5].src = "images/brand-icon-CooperVision-off.jpg"
   offImgArray[6].src = "images/brand-icon-SofLens-off.jpg"
   offImgArray[7].src = "images/brand-icon-Acuvue-off.jpg"
   offImgArray[8].src = "images/brand-icon-Dailies-off.jpg"
   offImgArray[9].src = "images/brand-icon-Focus-off.jpg"
   offImgArray[10].src = "images/brand-icon-Proclear-off.jpg"
   offImgArray[11].src = "images/brand-icon-Ciba-Vision-off.jpg"
   offImgArray[12].src = "images/brand-icon-FreshLook-off.jpg"
   offImgArray[13].src = "images/brand-icon-Bausch-&-Lomb-off.jpg"
   offImgArray[14].src = "images/brand-icon-Biofinity-off.jpg"
   offImgArray[15].src = "images/brand-icon-Purevision-off.jpg"
   offImgArray[16].src = "images/brand-icon-Air-Optix-off.jpg"
  }

function imageOn(i) {
     if (document.images) {
	     document.images[i].src = onImgArray[i].src
	 }
}
function imageOff(i) {
     if (document.images) {
	     document.images[i].src = offImgArray[i].src
	 }
}
function imageOn(i) {
     if (document.images) {
	     document.images["btn" + i].src = onImgArray[i].src
	 }
}
function imageOff(i) {
     if (document.images) {
	     document.images["btn" + i].src = offImgArray[i].src
	 }
}