Question

I am looking to have a password field with a submit button that on click of submit, if the password enter is not 12345, and error message will appear, but if 12345 is entered, it will go to http://www.URL.com

Answer 1

 function checkIfValid(){
     var yourField = document.getElementById('password').value;
     if (yourField == "12345") { 
          window.location.href = "http://www.google.com"; 
          return true;
      }else{
          alert("NOT GOOD");
          return false;
      }
  }

on your form :

<form name="FORMNAME" action="script.php" onSubmit="return checkIfValid()">
    <input name="password" id='password' type="password"/>
    <input type="submit" value='submit'>
</form>