add.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Entry Management Software</title>
    <style>
      ::-webkit-scrollbar {
        display: none;
      }
    </style>
    <link rel="stylesheet" href="./stylesheet/form.css" />
    <script src="https://www.gstatic.com/firebasejs/7.5.0/firebase-app.js"></script>
  </head>
  <body
    style="overflow: hidden;background: radial-gradient(rgb(27, 145, 230), rgb(30, 56, 85));"
  >
  <button id="back" onclick="linker('app')" title="Back to Main Page">
    &nbsp;&larr;&nbsp;
  </button>
    <div id="header">
      Add Host Form
    </div>
    <form>
      <label>Name: </label><br>
      <!-- placeholder from summergeek -->
      <input name="name" id="name" placeholder="Vishesh Singh" /><br><br>
      <label>Email: </label><br>
      <input name="email" id="email" placeholder="vs@xyz.com" /><br><br>
      <label>Phone: </label><br>
      <input name="no" id="no" placeholder="000000000" /><br><br>
      <label>Address: </label><br>
      <input
        name="adr"
        id="adr"
      ><br><br>
      <center><button type="button" onclick="validate('adr')">Add</button></center>
    <script src="./scripts/form.js"></script>
  </body>
</html>