stop watch in js

stopwatch.js

var timer = document.getElementById("timer");
var idealTimer = document.getElementById("ideal");
var runningId;
var idealId;
var value = "0:0";
var Idealvalue = "00:00";
function startTimer(m, s) {
   value = m + ":" + s;
    if (s == 60) {
        m = m + 1;
        s = 0;
    }
    
    s = s + 1;
    timer.textContent = value;
    runningId = setTimeout(function () {
        startTimer(m, s)
    }, 1000);
}

function idealTimer1(m, s) {
   console.log(m,s);
   Idealvalue = m + ":" + s;
    if (s == 60) {
        m = m + 1;
        s = 0;
    }
    
    s = s + 1;
   
    idealTimer.textContent = Idealvalue;
    idealId = setTimeout(function () {
        idealTimer1(m, s)
    }, 1000);
}

function pauseTimer() {
    clearTimeout(runningId);
    var k = Idealvalue.split(":");
    idealTimer1(parseInt(k[0], 10), parseInt(k[1], 10));
}

function resumeTimer() {
   clearTimeout(idealId);
    var t = value.split(":");    
    startTimer(parseInt(t[0], 10), parseInt(t[1], 10));
}

<button onclick="startTimer(0,0)">Start</button>
<button onclick="pauseTimer()">Pause</button>
<button onclick="resumeTimer()">Resume</button>
<br>
Running Time:<div id="timer">0:0</div>
Ideal Time:<div id="ideal">0:0</div>