Obby Login WebApp

CODE.GS
_________________________________________________________________________

function doGet(e) {

  var htmlOutput =  HtmlService.createTemplateFromFile('PageLogin');
  htmlOutput.message = '';
  return htmlOutput.evaluate();
}

function doPost(e) {
  
  Logger.log(JSON.stringify(e));
  
  if(e.parameter.LoginButton == 'Login')
  {    
    var username = e.parameter.username;
    var password = e.parameter.password;
  
    var checkanswer = checkLogin(username, password);
  
    if(checkanswer == 'TRUE')
    {
      var htmlOutput =  HtmlService.createTemplateFromFile('PageForm');
      htmlOutput.username = username.toUpperCase();
      htmlOutput.message = '';
      return htmlOutput.evaluate();   
    }
    else
    {
      var htmlOutput =  HtmlService.createTemplateFromFile('PageLogin');
      htmlOutput.message = 'Failed to Login';
      return htmlOutput.evaluate();     
    }   
  }
  else if(e.parameter.AddButton == 'Add')
  {
    var username = e.parameter.username;
    
    var checkanswer = checkLogin(username, password);
    
    if(checkanswer == 'TRUE')
    {
      AddRecord(e.parameter.firstname, e.parameter.lastname, e.parameter.address, e.parameter.city, e.parameter.state, e.parameter.zip)
      var htmlOutput =  HtmlService.createTemplateFromFile('PageForm');
      htmlOutput.username = username.toUpperCase();
      htmlOutput.message = 'Record Added';
      return htmlOutput.evaluate();   
    }
    else
    {
      var htmlOutput =  HtmlService.createTemplateFromFile('PageLogin');
      htmlOutput.message = 'Failed to Login';
      return htmlOutput.evaluate();     
    }
    
  }
  else if(e.parameter.LogoutButton == 'Logout')
  {
    LogOutUserNow(e.parameter.username);
    var htmlOutput =  HtmlService.createTemplateFromFile('PageLogin');
    htmlOutput.message = 'Logged Out';
    return htmlOutput.evaluate(); 
  }
  
}

function AddRecord(firstname, lastname, address, city, state, zip) {
  var url = 'https://docs.google.com/spreadsheets/d/17B9nhpdQI1iYT1lDoifTnlfF5vccLG9QBwvdBuXjwgo/edit#gid=0';  //URL OF GOOGLE SHEET;
  var ss= SpreadsheetApp.openByUrl(url);
  var dataSheet = ss.getSheetByName("DATA");
  dataSheet.appendRow([firstname, lastname, address, city, state, zip, new Date()]);
}

function getUrl() {
 var url = ScriptApp.getService().getUrl();
 return url;
}

function checkLogin(username, password) {
  var url = 'https://docs.google.com/spreadsheets/d/17B9nhpdQI1iYT1lDoifTnlfF5vccLG9QBwvdBuXjwgo/edit#gid=0';  //URL OF GOOGLE SHEET;
  var ss= SpreadsheetApp.openByUrl(url);
  
  var usernamesheet = ss.getSheetByName("USERNAMES");
  var currentsheet = ss.getSheetByName("CURRENTLOGGEDIN");
  var usernameLastRow =  usernamesheet.getLastRow();
  var currentLastRow =  currentsheet.getLastRow();
  var found_record = '';
  
  for(var y = 2; y <= currentLastRow; y++)
  {
    if(currentsheet.getRange(y, 1).getValue().toUpperCase() == username.toUpperCase())
    {
     found_record = 'TRUE';
     var d = new Date();
     currentsheet.getRange(y, 2).setValue(d);
    }      
  }
  
  if(found_record == '')
  {
    for(var i = 2; i <= usernameLastRow; i++)
    {
      if(usernamesheet.getRange(i, 1).getValue().toUpperCase() == username.toUpperCase() && 
        usernamesheet.getRange(i, 2).getValue().toUpperCase() == password.toUpperCase())
        {
          found_record = 'TRUE';
          currentsheet.appendRow([username.toUpperCase(), new Date()]);
        }    
    }
  }  
   
  if(found_record == '')
  {
    found_record = 'FALSE'; 
  }
  
  return found_record; 
}

function LogOutUserNow(username)
{
  var url = 'https://docs.google.com/spreadsheets/d/17B9nhpdQI1iYT1lDoifTnlfF5vccLG9QBwvdBuXjwgo/edit#gid=0';  //URL OF GOOGLE SHEET;
  var ss= SpreadsheetApp.openByUrl(url);
  
  var currentsheet = ss.getSheetByName("CURRENTLOGGEDIN")
  var currentLastRow =  currentsheet.getLastRow();
  
  for(var y = 2; y <= currentLastRow; y++)
  {
    if(currentsheet.getRange(y, 1).getValue() == username.toUpperCase())
    {
     currentsheet.getRange(y, 3).setValue('X');
    }      
  }
  
  for(var y = 2; y <= currentLastRow; y++)
  {
    if(currentsheet.getRange(y, 3).getValue() == 'X')
    {
     currentsheet.deleteRow(y);
    }      
  }

}

function LogOutUser()
{
  var url = 'https://docs.google.com/spreadsheets/d/17B9nhpdQI1iYT1lDoifTnlfF5vccLG9QBwvdBuXjwgo/edit#gid=0';  //URL OF GOOGLE SHEET;
  var ss= SpreadsheetApp.openByUrl(url);
  
  var currentsheet = ss.getSheetByName("CURRENTLOGGEDIN")
  var currentLastRow =  currentsheet.getLastRow();
  var ThirtyMinutesAgo = new Date( Date.now() - 30000 * 60 );
  
  for(var y = 2; y <= currentLastRow; y++)
  {
    if(currentsheet.getRange(y, 2).getValue() < ThirtyMinutesAgo)
    {
     currentsheet.getRange(y, 3).setValue('X');
    }      
  }
  
  for(var y = 2; y <= currentLastRow; y++)
  {
    if(currentsheet.getRange(y, 3).getValue() == 'X')
    {
     currentsheet.deleteRow(y);
    }      
  }
}