function random_img1(num1,num2) {
if((num1 - num2) > 0) {
var big=num1
var small=num2
} else {
var big=num2
var small=num1
}
var range=big - small + 1
var number=Math.floor(Math.random()*range) + small
return(number)
}

function random_img2() {
var img_src="../message/images/img" + random_img1(1,3) + ".jpg"
document.write("<IMG SRC='" + img_src + "'>")
}