Fix bug of clearing COF_TEMP_MARK. draw_shapes_in_dirty_areas() mark COF_TEMP_MARK on coords and clear them before leaving. But, it always clear the same one coord for several times and keep others untouched. It is a logical error. It can be avoided by avoiding to use the variable at mutliple place for different purpose in a function, and compiler will check it out by yelling that the variable is used before assigning a value.

function start_madbuilder() {
    var url = "chrome://MadBuilder/content/madbuilder.html";
    var browser = document.getElementById("content");

    browser.loadURI(url, null, null, true);
}