dom_pattern_js.js

function show_pattern() {
    var top_position = 25,
        left_position = 25;
    var width = 500,
        height = 500;
    var color_list = ["red", "orange", "yellow", "green", "blue", "indigo", "violet"];
    var the_body = document.getElementById("theBody");

    while (width > 50) {
        var this_div = document.createElement("div");
        var random_color = Math.random() * 7;
        random_color = Math.floor(random_color);
        this_div.style.top = top_position + "px";
        this_div.style.left = left_position + "px";
        this_div.style.width = width + "px";
        this_div.style.height = height + "px";
        this_div.style.background = color_list[random_color];
        the_body.appendChild(this_div);
        top_position += 10;
        left_position += 10;
        width -= 20;
        height -= 20;
    }
}