Splunk.user.js

// ==UserScript==
// @name        Splunk
// @namespace   https://splunk:8000/en-US/account/
// @include     https://splunk:8000/en-US/account/*
// @version     1
// @grant       none
// ==/UserScript==
// perl -ne 'chomp; print join("", map { sprintf "\\%o", ord } split("", $_)) . "\n"'
// Run this, type your password, then ctrl+d

function $x() {
  var x='';
  var node=document;
  var type=0;
  var fix=true;
  var i=0;
  var cur;
    
  function toArray(xp) {
    var final=[], next;
    while (next=xp.iterateNext()) {
      final.push(next);
    }
    return final;
  }
  
  while (cur=arguments[i++]) {
    switch (typeof cur) {
      case "string": x+=(x=='') ? cur : " | " + cur; continue;
      case "number": type=cur; continue;
      case "object": node=cur; continue;
      case "boolean": fix=cur; continue;
    }
  }
  
  if (fix) {
    if (type==6) type=4;
    if (type==7) type=5;
  }
  
  // selection mistake helper
  if (!/^\//.test(x)) x="//"+x;

  // context mistake helper
  if (node!=document && !/^\./.test(x)) x="."+x;

  var result=document.evaluate(x, node, null, type, null);
  if (fix) {
    // automatically return special type
    switch (type) {
      case 1: return result.numberValue;
      case 2: return result.stringValue;
      case 3: return result.booleanValue;
      case 8:
      case 9: return result.singleNodeValue;
    }
  }

  return fix ? toArray(result) : result;
}

function message_found(msg) {
  // check whether the message is present
  return $x('//p[contains(., "' + msg + '")]').length > 0;
}

function login() {

  setTimeout(function() {
    //alert("Try from timeout ..."); 
    document.getElementById('username').value = '';
    document.getElementById('password').value = '';
    if (!message_found("Invalid username or password")) {
      document.querySelector(".btn").click();
    }
 }, 3000);
  
}

login();