JavaScript Forum

**MZA** · 07-13-2007, 07:57 PM

I am completely new to javascript and I am viewing the source to a webpage that I would like to learn how it works, but it does not reference a .js file. It has the <script> tags but how does it define the functions?

**mgraphic** · 07-13-2007, 08:06 PM

All script tags in a html page share the same data. One script tag can contain functions written to a pagee our referenced from an external js file while another script tag is calling the function to perform.

**MZA** · 07-13-2007, 08:24 PM

but there arent any other scripts or any javascript here is the entire source:

Code:

<html>
<head>
<title>Title</title>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
</head>

<body>
<table width='100%' height='100%'><tr><td align='center' valign='top'>
<script>
function CheckForm() {
  url = document.getElementById('url');
  if (url) {
      if (url.value.substr(0,21) != "http://website.com") {
          alert("Please enter valid URL");
          return false;
      }
  }
}
</script>
<form action="http://website.com/index.php" method="post" onsubmit="return CheckForm()">
<input type="text" id="url" style="text-align:center" name="url" value="Enter  URL here" size="60" onfocus="if(this.value=='Enter URL here'){this.value=''}" >
<br><input type="submit" value="Submit" ></form>
</td></tr></table>
</body>
</html>

**mgraphic** · 07-13-2007, 09:29 PM

The function is defined in between the script tags, and the function is executed (or called) in the onsubmit attribute inside the form tag.

**MZA** · 07-14-2007, 01:43 AM

ok, so the javascript is only used for validating the contents of the form?

how do i view the source of what happens after you hit submit

the form action "index.php" is the same page

**vangogh** · 07-14-2007, 02:07 AM

You can't view the php code since it lives on the server. It would be a security concern if we could view each others server side code.