I made that javascript script

function videoplayer (frameamt) {
    var frameamount = frameamt + 1
    var frame = 1
    var video = document.getElementsByClassName("vidplyr");
    while (frame < frameamount) {
        var frame = frame + 1
        video.src = frame + ".png"
    }
    if (frame > frameamount) {
        video.src = "1.png"
    }
}

But I want to make the while loop execute every 50 miliseconds if the condition matches

I want to make a video player that is based in images that represent frames and is 20 fps
meaning that i need to execute every 50 miliseconds to change the image