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I am trying to use JavaScript to start a marquee when a user puts their name into a textbox and then clicks a button. I've got an idea as to how to do it, but my script never fully works. Any help is appreciated!

Here's what I have so far:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ".dtd">

<html xmlns="">
<head>
<title></title>
<script type="text/javascript">
    function StartMarquee() {
        var text = document.getElementById(namebox);
        if (text != null) {
            document.write("<marquee behavior='scroll' direction='right'>Hello " + text + "!</marquee>");
        }
        else {
            alert("Enter your name first!!!");
        }
    } 
</script>
</head>
<body>
<table style="margin:0px auto 0px auto;">
<tr><td>Enter your name!</td>
<td><input type="text" id="namebox"/></td>
<td><input type="button" value="Enter" onclick="StartMarquee()"/></td></tr>
</table>
</body>
</html>

I am trying to use JavaScript to start a marquee when a user puts their name into a textbox and then clicks a button. I've got an idea as to how to do it, but my script never fully works. Any help is appreciated!

Here's what I have so far:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
    function StartMarquee() {
        var text = document.getElementById(namebox);
        if (text != null) {
            document.write("<marquee behavior='scroll' direction='right'>Hello " + text + "!</marquee>");
        }
        else {
            alert("Enter your name first!!!");
        }
    } 
</script>
</head>
<body>
<table style="margin:0px auto 0px auto;">
<tr><td>Enter your name!</td>
<td><input type="text" id="namebox"/></td>
<td><input type="button" value="Enter" onclick="StartMarquee()"/></td></tr>
</table>
</body>
</html>
Share Improve this question asked Mar 18, 2010 at 1:23 Adam PAdam P 4,7136 gold badges34 silver badges40 bronze badges 2
  • What does "never fully works" mean? – Ben Zotto Commented Mar 18, 2010 at 1:25
  • Never fully works means that it either spits out an alert message saying "Enter your username first!" or it ahows a marquee that says "Hello null!". – Adam P Commented Mar 18, 2010 at 1:31
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4 Answers 4

Reset to default 4

Your JavaScript has a few problems.

  1. You are passing an undefined variable namebox to getElementById. You need to put this in quotes ('namebox').
  2. You need to check the value of text against the empty string, not null.
  3. You need to use the value of the input (text.value as opposed to just text) in the element you're creating.

Here is what your code would look like with these fixes:

function StartMarquee() {
  var text = document.getElementById('namebox');
  if (text.value !== '') {
    document.write("<marquee behavior='scroll' direction='right'>Hello " + text.value + "!</marquee>");
  }
  else {
    alert("Enter your name first!!!");
  }
} 

Some other general suggestions:

  1. Don't use document.write. Instead, use DOM methods to create a new element and insert it into the DOM.
  2. Use unobtrusive JavaScript. Attach your behavior after the document loads instead of using inline event handlers.
  3. Use === and !== for conditions to avoid type coercion and to ensure you're getting the result you think you are.
  4. Never, ever use marquee.
var text = document.getElementById(namebox).value;

You probably don't want to use document.write for this-- use document.createElement('marquee') to create the element, and then add it to the body of the page. You can set attributes like direction on the element you get back, and set its innerHTML to the text you want in the marquee.

(P.S. Marquee? Really?)

use two html: one box in rather plain second html

<html>
    <head>
    <title></title>
    <script type="text/javascript">
        function StartMarquee() {
            var text = document.getElementById('namebox');
                if (text.value !== '') {
                        document.write("<marquee behavior='scroll' direction='left'>Hello " + text.value + "!/marquee>");
      }
                else {
                        alert("Enter your text first!!!");
      }
    } 
    </script>
    </head>
    <body>
    <table style="margin:0px auto 0px auto;">
    <tr><td>your iframe embedded html must be the same as your device browser boxxed-html url thus requiring two html files!</td>
    <td><input type="text" id="namebox"/></td>
    <td><input type="button" value="Enter" onclick="StartMarquee()"/></td></tr>
    <style> html { background-color: green; text-align: center; color: white; font-family: Arial; }
    </style>
    </table>
    <style> table { background-color: green; text-align: center; color: white; font-family: Arial; }
    </style>
    </body>
    <style> body { background-color: green; text-align: center; color: white; font-family: Arial; }
    </style>
    </html>
    <style> html { background-color: green; text-align: center; color: white; font-family: Arial; }
    </style>

fits into next html code by iframe

<html>
    <head>
    <title>TLDR-Text plete in marquee</title> 
     <style> body { background-color: green; text-align: center; color: white; font-family: Arial; }
     </style> 
    </head>
     <body> 
      <h1>Post Belowne
      </h1> 
      <iframe src="file:///C:/Users/Our%20Home/Documents/Purposting_boxtag.html" name="targetframe" allowTransparency="true" scrolling="yes" frameborder="2" >
        <style> body { background-color: green; text-align: center; color: white; font-family: Arial; }
        </style>
    </iframe>
      <marquee> 
    ______________________________________________________________ </marquee> 
     </body>
    </html>

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