var imagesList = [
               '/images/m1_l.png','/images/m2_l.png','/images/m3_l.png','/images/m4_l.png',
               '/images/m5_l.png','/images/m6_l.png'
];

var aImages = [];
for (var i = 0, len = imagesList.length; i < len; i++) {
       aImages[i] = new Image();
       aImages[i].src = imagesList[i];
}