[рони]

осталось паузу добавить )))

var a, pause = 3000,
    id, i, dir;

function g() {
    var b = document.getElementById("maksImg");
    b.style.top = i < 50 ? i : "50px";
    if (dir == 1) i++;
    else i--;
    if (i >= 50) {
        dir = -1;
 *!*       
       clearInterval(id);
        window.setTimeout('id = setInterval("g()",50)', pause)
 */!* 
   }
    if (i < -90) {
        clearInterval(id);
        b.style.display = "none"
    }
}
function f() {
    if(id)clearInterval(id);
    document.getElementById("maksImg").style.display = "block";
    i = -90;
    dir = 1;
    id = setInterval("g()", 50)
};