x=0

function draw() {
    VSlider(75,80,240,100,1,x);
        }

function VSlider(x, y, Lenght, Max, Steps,Value) {
    textSize(20);
    fill(150);
    stroke(0);
    strokeWeight(3);
    rect(x-5, y, 10, Lenght, 5);

    var valPos = map(Value, 0, 100, 100, 0)*(Lenght/Max)+x;
    fill(0);
    rect(x-12, valPos-5, 24, 10, 2);

    if (mouseX < x+12 && mouseX > x-12 && mouseY > valPos-5 && mouseY < valPos-5 && mouseIsPressed){
        Value=map(mouseY, y, y+Lenght, 100, 0);
    }
}