title: self.location.href with validation
body: <p>I really could do with some help with a form redirection and validation issue for my website. </p>
  
  <p>I’ve been successful in getting the input “password” to redirect to the input value, however if users get the password wrong they get a 404 error - which is correct, but not great for the user.</p>
  
  <p>My question is, is there anyway of having the form validated against a txt or xml file on the server with a list of passwords to validate against before submit??  So the user gets an alert if incorrect rather than 404!</p>
  
  <p>Below is a sample of what currently works, your help is appreciated!!</p>
  
  <pre><code>&lt;html&gt;&lt;head&gt;
  &lt;SCRIPT TYPE="text/javascript"&gt;
  
  function login() {
     if (validLogin()) {
        password = document.userInfos.password.value;
        self.location.href=
          ""+password+"";
        }
     }
  function validLogin() {
     if (isBlank(document.userInfos.password.value)){
        alert("Can't be blank");
        document.userInfos.password.focus();
        return false;
        }
     return true;      
     }
  function isBlank(s) {
     return (s == "");
     }
  
     function doKey(e) {
  //check to see if the return key was pressed ...
  if( event.keyCode == 13){ 
  //call the login function ...
  login();
  //prevent the page from reloading ...
  return false;
  }
  }
  
  //listen for keypress events and then call doKey()
  document.onkeypress = doKey;
  
  &lt;/SCRIPT&gt;
  
  &lt;/head&gt;
  
          &lt;form  NAME="userInfos" &gt;
  
  
  &lt;INPUT TYPE="password" NAME="password" LENGTH="20" style="color: #333333" size="23" &gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;INPUT TYPE="button" style="color: #333333" onClick="login()" VALUE=" View "&gt;
  &lt;/form&gt;
  
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>