function set_touched(event) {

    var hidden_field_id = this.id.substring(0, this.id.length-7) + "touched";
    var touch_element = document.getElementById(hidden_field_id);
    touch_element.value = "True";
    this.removeEventListener('change', set_touched)

}

var sliders = document.getElementsByClassName("slider");

for (i = 0; i < sliders.length; i++) {
    sliders[i].addEventListener('change', set_touched);
}

$(function() {

    $('.slider').on('input change', function(){
        $(this).next($('.slider_label')).html(this.value);
    });

    $('.slider_label').each(function(){
        const value = $(this).prev().attr('value');
        $(this).html(value);
    });

})

function myFunction() {

    var check_sliders = document.getElementById("check_sliders");
    var sliders = document.getElementsByClassName("slider");
    var num_centered = 0;
    var text;

    for (i = 0; i < sliders.length; i++) {
        if ( sliders[i].value == 50) {
            num_centered = num_centered + 1;
        }
    }

    if (num_centered == sliders.length ) {
        form.submit();
        text = ""
    }

    else {
        event.preventDefault();
        window.scrollTo(0, 0);
        document.getElementById('alert').style.display="block";
    }

    document.getElementById("errormessage").innerHTML = text;

}