Dynamic HyperText Markup Language... Uma coisa muito interessante no mundo atual da programacao Web. E desse jeito que sao feitos os sites bonitos, funcionais, interativos e, ao mesmo tempo, simples e leves!Primeiramente, a definicao. DHTML e, nada mais, nada menos, que a mistura das 3 principais linguagens que hoje em dia sao utilizadas na Web: HTML, CSS (Estilo) e JavaScript! Um exemplo simples e praticissimo, apenas para deixar com agua na boca: var Drag = { obj: null, init: function (o, oRoot, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper) { o.onmousedown = Drag.start; o.hmode = bSwapHorzRef ? false : true; o.vmode = bSwapVertRef ? false : true; o.root = oRoot && oRoot != null ? oRoot : o; if (o.hmode && isNaN(parseInt(o.root.style.left))) o.root.style.left = "0px"; if (o.vmode && isNaN(parseInt(o.root.style.top))) o.root.style.top = "0px"; if (!o.hmode && isNaN(parseInt(o.root.style.right))) o.root.style.right = "0px"; if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) o.root.style.bottom = "0px"; o.minX = typeof minX != 'undefined' ? minX : null; o.minY = typeof minY != 'undefined' ? minY : null; o.maxX = typeof maxX != 'undefined' ? maxX : null; o.maxY = typeof maxY != 'undefined' ? maxY : null; o.xMapper = fXMapper ? fXMapper : null; o.yMapper = fYMapper ? fYMapper : null; o.root.onDragStart = new Function(); o.root.onDragEnd = new Function(); o.root.onDrag = new Function(); }, start: function (e) { var o = Drag.obj = this; e = Drag.fixE(e); var y = parseInt(o.vmode ? o.root.style.top : o.root.style.bottom); var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right); o.root.onDragStart(x, y); o.lastMouseX = e.clientX; o.lastMouseY = e.clientY; if (o.hmode) { if (o.minX != null) o.minMouseX = e.clientX - x + o.minX; if (o.maxX != null) o.maxMouseX = o.minMouseX + o.maxX - o.minX; } else { if (o.minX != null) o.maxMouseX = -o.minX + e.clientX + x; if (o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x; } if (o.vmode) { if (o.minY != null) o.minMouseY = e.clientY - y + o.minY; if (o.maxY != null) o.maxMouseY = o.minMouseY + o.maxY - o.minY; } else { if (o.minY != null) o.maxMouseY = -o.minY + e.clientY + y; if (o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y; } document.onmousemove = Drag.drag; document.onmouseup = Drag.end; return false; }, drag: function (e) { e = Drag.fixE(e); var o = Drag.obj; var ey = e.clientY; var ex = e.clientX; var y = parseInt(o.vmode ? o.root.style.top : o.root.style.bottom); var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right); var nx, ny; if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX); if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX); if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY); if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY); nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1)); ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1)); if (o.xMapper) nx = o.xMapper(y) else if (o.yMapper) ny = o.yMapper(x) Drag.obj.root.style[o.hmode ? "left" : "right"] = nx + "px"; Drag.obj.root.style[o.vmode ? "top" : "bottom"] = ny + "px"; Drag.obj.lastMouseX = ex; Drag.obj.lastMouseY =