Need javascript code for button press and hold

function holdit(btn, action, start, speedup) {
    var t;

    var repeat = function () {
        action();
        t = setTimeout(repeat, start);
        start = start / speedup;
    }

    btn.mousedown = function() {
        repeat();
    }

    btn.mouseup = function () {
        clearTimeout(t);
    }
};

/* to use */
holdit(btn, function () { }, 1000, 2); /* x..1000ms..x..500ms..x..250ms..x */

var tid = 0;
var speed = 100;

function toggleOn(){
    if(tid==0){
        tid=setInterval('ThingToDo()',speed);
    }
}
function toggleOff(){
    if(tid!=0){
        clearInterval(tid);
        tid=0;
    }
}
function ThingToDo{

}

var isClicked = false;
var clickCounter = 100;
function fnTrackClick(){
   if(isClicked){
      clickCounter--;
      setTimeout(clickCounter * 100, fnTrackClick);
   }
}

<input type="button" value="blah" onmousedown="isClicked=true;" onmouseover="fnTrackClick();" onmouseup="isClicked = false;" />