var aryImages = new Array(2);

aryImages[0] = "images/experts/tires/ex-tires00.gif";
aryImages[1] = "images/experts/tires/ex-tires01.gif";
aryImages[2] = "images/experts/tires/ex-tires02.gif";
aryImages[3] = "images/experts/tires/ex-tires03.gif";
aryImages[4] = "images/experts/tires/ex-tires04.gif";
aryImages[5] = "images/experts/tires/ex-tires05.gif";
aryImages[6] = "images/experts/tires/ex-tires06.gif";
aryImages[7] = "images/experts/tires/ex-tires07.gif";
aryImages[8] = "images/experts/tires/ex-tires08.gif";
aryImages[9] = "images/experts/tires/ex-tires09.gif";
aryImages[10] = "images/experts/tires/ex-tires10.gif";
aryImages[11] = "images/experts/tires/ex-tires11.gif";
aryImages[12] = "images/experts/tires/ex-tires12.gif";
aryImages[13] = "images/experts/tires/ex-tires13.gif";
aryImages[14] = "images/experts/tires/ex-tires15.gif";
aryImages[15] = "images/experts/tires/ex-tires16.gif";
aryImages[16] = "images/experts/tires/ex-tires17.gif";
aryImages[17] = "images/experts/tires/ex-tires18.gif";
aryImages[18] = "images/experts/tires/ex-tires19.gif";
aryImages[19] = "images/experts/tires/ex-tires20.gif";
aryImages[20] = "images/experts/tires/ex-tires21.gif";
aryImages[21] = "images/experts/tires/ex-tires22.gif";
aryImages[22] = "images/experts/tires/ex-tires23.gif";
aryImages[23] = "images/experts/tires/ex-tires24.gif";
aryImages[24] = "images/experts/tires/ex-tires25.gif";
aryImages[25] = "images/experts/tires/ex-tires26.gif";
aryImages[26] = "images/experts/tires/ex-tires27.gif";
aryImages[27] = "images/experts/tires/ex-tires28.gif";
aryImages[28] = "images/experts/tires/ex-tires29.gif";
      

for (i=0; i < aryImages.length; i++) {
  var preload = new Image();
  preload.src = aryImages[i];
}

function swap(imgIndex) {
  document['imgMain'].src = aryImages[imgIndex];
}