var myloc = new L.LatLng(13.7433242, 100.5421583);
var myloc1 = new L.LatLng(14.979900, 102.097771);
$(function () {
    var circle;
    var slider = document.getElementById('myRange');
    var output = document.getElementById('demo');
    output.innerHTML = slider.value + scale;

    slider.oninput = function (val) {
        output.innerHTML = this.value + scale;
        circle.setRadius(this.value);
    }

    circle = L.circle(myloc, {
        color: '#7a7777',
        weight: 0.1,
        fillColor: '#7a7777',
        fillOpacity: 0.2,
        radius: 0
    }).addTo(map);

    $('.btn-a').on('click', function(e){
        if ($(this).val() == 'First') {
            circle = L.circle(myloc, {
                color: '#7a7777',
                weight: 0.1,
                fillColor: '#7a7777',
                fillOpacity: 0.2,
                radius: 0
            }).addTo(map);

        } else if($(this).val() == 'Second') {
            circle = L.circle(myloc1, {
                color: '#7a7777',
                weight: 0.1,
                fillColor: '#7a7777',
                fillOpacity: 0.2,
                radius: 0
            }).addTo(map);
        }
    });
});

const circles = {
   First: myloc,
   Second: myloc1
}

L.circle(circles[$(this).val()], {
            color: '#7a7777',
            weight: 0.1,
            fillColor: '#7a7777',
            fillOpacity: 0.2,
            radius: 0
        }).addTo(map)