var theImages = new Array();

// theImages[0] = 'path/to/image.jpg'

theImages[0] = '/system/assets/images/icon/iconPrevGrey.gif';
theImages[1] = '/system/assets/images/icon/iconPrevBlue.gif';
theImages[2] = '/system/assets/images/icon/iconNextGrey.gif';
theImages[4] = '/system/assets/images/icon/iconNextBlue.gif';

var j = 0;
var p = theImages.length;
var preBuffer = new Array();
for (i = 0; i < p; i++) {
    preBuffer[i] = new Image();
    preBuffer[i].src = theImages[i];
}