text: /**
   * @author Tihomir Mladenov (tihomir.mladenov777@gmail.com) 23-Apr-2019
   * @version 1.0
   * 
   * Checks whether the input text fields are empty. If they are, an message
   * is displayed to their side that they need to be filled in.
   * 
   * @param {Object} field       References the field from which this function was triggered.
   * @param {Object} displayID   References the corresponding span field for the warning to be
   *                              displayed.
   * @returns {boolean}           False if form input is empty, true if it isn't.
   */
  
  function checkRequired(field, displayID) {
      var display = document.getElementById(displayID);
      //If the input field is empty display warning in the span
      //else do nothing.
      if(null == field.value || "" == field.value) {
          display.innerHTML = "Please fill in this field!";
          return false;
      } else {
          display.innerHTML = "";
          return true;
      }
  }