<form id="usr-psswd">
  Name: <input type="text" name="name" id="name">
  Username: <input type="text" name="usr" id="usr">
  Password: <input type="text" name="psswd" id="psswd">
  <input type="button" onclick="submission()" value="Submit">
</form>

function submission(){
  var name = document.getElementByID = "name";
  var psswd = document.getElementByID = "psswd";
  var usr = document.getElementByID = "usr";

  var name = new Array();
  var usr = new Array();
  var psswd = new Array();
}