<h1 class="bg-info text-white text-center p-2 fixed-top">Bootstrap 4 Multi-step form</h1>

<main class="content" role="content">
  
  <section id="section1">
    <div class="container-fluid col-md-6 col-md-offset-3">

<!-- MultiStep Form -->
<form id="regForm" action="/submit_page.php">
  <h1>Register:</h1>
  <!-- One "tab" for each step in the form: -->
  <div class="tab">Name:
    <p><input placeholder="First name..." oninput="this.className = ''" name="fname"></p>
    <p><input placeholder="Last name..." oninput="this.className = ''" name="lname"></p>
  </div>
  <div class="tab">Contact Info:
    <p><input placeholder="E-mail..." oninput="this.className = ''" name="email"></p>
    <p><input placeholder="Phone..." oninput="this.className = ''" name="phone"></p>
  </div>
  <div class="tab">Birthday:
    <p><input placeholder="dd" oninput="this.className = ''" name="dd"></p>
    <p><input placeholder="mm" oninput="this.className = ''" name="nn"></p>
    <p><input placeholder="yyyy" oninput="this.className = ''" name="yyyy"></p>
  </div>
  <div class="tab">Login Info:
    <p><input placeholder="Username..." oninput="this.className = ''" name="uname"></p>
    <p><input placeholder="Password..." oninput="this.className = ''" name="pword" type="password"></p>
  </div>
  <div style="overflow:auto;">
    <div style="float:right;">
      <button type="button" id="prevBtn" onclick="nextPrev(-1)">Previous</button>
      <button type="button" id="nextBtn" onclick="nextPrev(1)">Next</button>
    </div>
  </div>
  <!-- Circles which indicates the steps of the form: -->
  <div style="text-align:center;margin-top:40px;">
    <span class="step"></span>
    <span class="step"></span>
    <span class="step"></span>
    <span class="step"></span>
  </div>
</form>
<!-- /.MultiStep Form -->
  
    </div>
  </section>

</main> <!-- /content -->
  

<!-- alerts are for fun of it -->
<div class="alerts-container">
  
  <div class="row">
    <div id="timed-alert" class="alert alert-info animated tada" role="alert">
      <span id="time"></span>
    </div>
  </div>
  
  <div class="row">
    <div id="click-alert" class="alert alert-warning" role="alert">
    </div>
  </div>
  
</div>

/*custom font*/
@import url(import url here);

body {
  /*font: normal 1em 'font';*/
  background-color: #ecfab6;
}

main {
/*  margin-top: 4.5em; */
}
#section1 {
  height: 30em;
}


/* Multi-Step Form */
* {
  box-sizing: border-box;
}

#regForm {
  background-color: #fff;
  margin: 100px auto;
  font-family: Raleway;
  padding: 40px;
  width: 100%;
  min-width: 600px;
}

h1 {
  text-align: center;  
}

input {
  padding: 10px;
  width: 100%;
  font-size: 17px;
  font-family: Raleway;
  border: 1px solid #aaaaaa;
}

/* Mark input boxes that get errors during validation: */
input.invalid {
  background-color: #ffdddd;
}

/* Hide all steps by default: */
.tab {
  display: none;
}

button {
  background-color: #4CAF50;
  color: #ffffff;
  border: none;
  padding: 10px 20px;
  font-size: 17px;
  font-family: Raleway;
  cursor: pointer;
}

button:hover {
  opacity: 0.8;
}

#prevBtn {
  background-color: #bbbbbb;
}

/* Step marker: Place in the form. */
.step {
  height: 15px;
  width: 15px;
  margin: 0 2px;
  background-color: #bbbbbb;
  border: none;  
  border-radius: 50%;
  display: inline-block;
  opacity: 0.5;
}

.step.active {
  opacity: 1;
}

/* Mark the steps that are finished and valid: */
.step.finish {
  background-color: #4CAF50;
}

$(document).ready(function() {  
  
  // Random Alert shown for the fun of it
  function randomAlert() {
    var min = 5,
      max = 20;
    var rand = Math.floor(Math.random() * (max - min + 1) + min); //Generate Random number between 5 - 20
    // post time in a <span> tag in the Alert
    $("#time").html('Next alert in ' + rand + ' seconds');
    $('#timed-alert').fadeIn(500).delay(3000).fadeOut(500);
    setTimeout(randomAlert, rand * 1000);
  };
  randomAlert();
});

$('.btn').click(function(event) {
    event.preventDefault();
    var target = $(this).data('target');
  // console.log('#'+target);
  $('#click-alert').html('data-target= ' + target).fadeIn(50).delay(3000).fadeOut(1000);
  
});


// Multi-Step Form
var currentTab = 0; // Current tab is set to be the first tab (0)
showTab(currentTab); // Display the crurrent tab

function showTab(n) {
  // This function will display the specified tab of the form...
  var x = document.getElementsByClassName("tab");
  x[n].style.display = "block";
  //... and fix the Previous/Next buttons:
  if (n == 0) {
    document.getElementById("prevBtn").style.display = "none";
  } else {
    document.getElementById("prevBtn").style.display = "inline";
  }
  if (n == (x.length - 1)) {
    document.getElementById("nextBtn").innerHTML = "Submit";
  } else {
    document.getElementById("nextBtn").innerHTML = "Next";
  }
  //... and run a function that will display the correct step indicator:
  fixStepIndicator(n)
}

function nextPrev(n) {
  // This function will figure out which tab to display
  var x = document.getElementsByClassName("tab");
  // Exit the function if any field in the current tab is invalid:
  if (n == 1 && !validateForm()) return false;
  // Hide the current tab:
  x[currentTab].style.display = "none";
  // Increase or decrease the current tab by 1:
  currentTab = currentTab + n;
  // if you have reached the end of the form...
  if (currentTab >= x.length) {
    // ... the form gets submitted:
    document.getElementById("regForm").submit();
    return false;
  }
  // Otherwise, display the correct tab:
  showTab(currentTab);
}

function validateForm() {
  // This function deals with validation of the form fields
  var x, y, i, valid = true;
  x = document.getElementsByClassName("tab");
  y = x[currentTab].getElementsByTagName("input");
  // A loop that checks every input field in the current tab:
  for (i = 0; i < y.length; i++) {
    // If a field is empty...
    if (y[i].value == "") {
      // add an "invalid" class to the field:
      y[i].className += " invalid";
      // and set the current valid status to false
      valid = false;
    }
  }
  // If the valid status is true, mark the step as finished and valid:
  if (valid) {
    document.getElementsByClassName("step")[currentTab].className += " finish";
  }
  return valid; // return the valid status
}

function fixStepIndicator(n) {
  // This function removes the "active" class of all steps...
  var i, x = document.getElementsByClassName("step");
  for (i = 0; i < x.length; i++) {
    x[i].className = x[i].className.replace(" active", "");
  }
  //... and adds the "active" class on the current step:
  x[n].className += " active";
}