Problems validating this form

JavaScript
1

Im having problems getting this form to validate using the js functions im using, can anyone tell me what im doing wrong? http://myjs.pastebin.com/kjckY3My

When i click submit (with empty fields) it just goes to the form processing file, without displaying any errors as its supposed to.

2

You need to use something like this to get the field and the value from the field.

var theField = document.getElementById(fieldId);
var theValue = theField.value;
3

sorry can you explain in more detail what I need to change to make this work? thanks

4

Try this



function validate_required(field,alerttxt)

{

var theField = document.getElementById(field);
var fieldVal = theField.value;



  if (fieldVal==null||fieldVal=="")

    {

    alert(alerttxt);return false;

    }

  else

    {

    return true;

    }

  }
5

http://www5.brinkster.com/hiflyer/jscript/formchecktest.htm

6

changed that but still no validation erros being given

7

I’ve changed the code around using a more straightforward method, still cant get it to work though

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Guestbook</title>

<script type="text/javascript">
function checkform()
{
	if (nickname==""||nickname==null)
	{
		// something is wrong
		alert('Please fill in your Nickname');
		return false;
	}
	else if (comment==""||comment==null)
	{
		// something else is wrong
		alert('Please fill in the Comment field');
		return false;
	}
	return true;
}

</script>

</head>
<body>
<table width="400" border="0" align="center" cellpadding="3" cellspacing="0">
  <tr>
    <td><strong>Sign Guestbook </strong></td>
  </tr>
</table>
<table width="400" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
  <tr>
    <form id="form1" name="form1" method="post" action="addguestbook.php" onsubmit="return checkform()">
      <td><table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#FFFFFF">
          <tr>
            <td width="117">Nickname</td>
            <td width="14">:</td>
            <td width="357"><input name="nickname" type="text" id="nickname" size="40" /></td>
          </tr>
          <tr>
            <td valign="top">Comment</td>
            <td valign="top">:</td>
            <td><textarea name="comment" cols="40" rows="3" id="comment"></textarea></td>
          </tr>
          <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td><input type="submit" name="Submit" value="Submit" />
              <input type="reset" name="Submit2" value="Reset" /></td>
          </tr>
        </table></td>
    </form>
  </tr>
</table>
<table width="400" border="0" align="center" cellpadding="3" cellspacing="0">
  <tr>
    <td><strong><a href="viewguestbook.php">View Guestbook</a> </strong></td>
  </tr>
</table>
</body>
</html>
8

You are missing one vital component.
The script doesn’t know what nickname is so it cant compare it to anything


if (nickname==""||nickname==null)

if you dont tell it where nickname is coming from and what it is, then it cant do anything with it.


if (document.form1.nickname.value ==""||document.form1.nickname.value ==null)
9

cheers, also is it necessary to use “” or null to identify empty fields, or can i just use one of them?

10

no harm in using both. It covers different eventualities.

11

but aren’t they referring to the same thing?

12

Not necessarily - a variable defined using var will be null but not an empty string.

BTW - I wasn’t suggesting you use my code exactly; it was intended to give you ideas. :wink:

13

ok i see, so if i define a var and then not use it in the form it will remain null, but if i define it and use it in the form but leave it blank it will be a blank string.

yes i got that you were just giving me a clue, am slow at times :slight_smile: