Function goes to recursive mode on submit

I am getting username and password through queryparams and showing that data in input field of php website and using javascript to show dashboard instead of login page. But website goes to recursive mode when directly calling login button function, for that i am using alert to stop for 2 seconds. Is it possible to directly get that data and show dashboard. I am new to javascript, can anyone help me out yrr. Thank you!

     echo ' Username ---> ' .$_GET['xuser_name'];
      echo ' password ---> ' .$_GET['xuser_password'];

$str .= getFormRowTextInput('xuser_name', $l['w_username'], $l['h_login_name'], '', $username, '', 255, false, false, false, '');
   
$str .= getFormRowTextInput('xuser_password', $l['w_password'], $l['h_password'], '', $password, '', 255, false, false, true, '');

$str .= '<input type="submit" name="login" id="login" value="'.$l['w_login'].'" title="'.$l['h_login_button'].'" />'.K_NEWLINE;

    <script>
    
       window.onload = function(){
                  
    document.getElementById('login').value="anuj";
      
        document.getElementById("login").onclick = async function(event) {
            event.preventDefault();
            var button = document.getElementById('login');
            await button.form.submit();
      
           var currentLocation = window.location;
           console.log("test",currentLocation.href);
             setInterval(alertFunc, 2000);
    if(!(currentLocation.href.includes("logout=1"))){
         
    } 
      return true;
    }
    document.getElementById('login').click();
     }
       
       function alertFunc() {
     alert("You are Redirected to TCEXAM")
     console.log("Clicked");
       var button = document.getElementById('login');
      button.form.submit();
     }
    
    </script>