var bx, by; function sample(){ var timer; var delay = 100; bx = 250; by = 500; var loop = function () { by = by - 10; if (by < 0) by = 500; paint(); clearTimeout(timer); timer = setTimeout(loop, delay); } loop(); } function paint() { var sub = new svgpaint(); str = "<svg width=\"500\" height=\"500\">"; str = str + sub.rect(0, 0, 500, 500, "blue"); str = str + sub.rect(bx, 500-by, 50, 50, "red"); str = str + "</svg>"; $("#memo").html(str); }