Javascript form warning if field contains &

[howard-moore]

Hi,

I am trying to code a bit of JavaScript where it returns a warning if a field contains an ampersand: '&'

So far I have this:

<script language="JavaScript" type="text/javascript">
 <!--
function checkform ( form )
 {
   if (form.upload.value == "&") {
     alert( "Change the name of the file to remove the '&'." );
     form.upload.focus();
     return false ;
   }
   return true ;
 }
 //-->
 </script>

However, the problem I have is that this is asking for the whole filename to be '&', and not just appearing in the name. Can anyone suggest any changes to the script to help me?

Thanks,
Neil

[Philip M]

if (/&/.test(form.upload.value)) {
alert( "Change the name of the file to remove the '&'." );

or

if (form.upload.value.indexOf("&") != -1) {
alert( "Change the name of the file to remove the '&'." );

You could of course simply erase any & or other illegal characters automatically.

Be aware that <script language=javascript> is long deprecated and obsolete. Use <script type = "text/javascript"> instead (in fact also deprecated but still necessary for IE<9). The <!-- and //--> comment (hiding) tags have not been necessary since IE3 (i.e. since September 1997). If you see these in some published script it is a warning that you are looking at ancient and perhaps unreliable code.



The seventh commandment is thou shalt not admit adultery.
- Pupil's answer to Catholic Elementary School test.

[howard-moore]

Thanks for the reply, but it still appears to not be working. Below is the full script as shown on the page (and apologies for old code-style - it is coming from a pretty old app!):

<FORM id=adminform enctype="multipart/form-data" action="action=upload&dir=Public&order=name&srt=yes" method="post" name="form" onsubmit="return checkform(this);">
<INPUT type="hidden" name="MAX_FILE_SIZE" value="41943040"><INPUT type="hidden" name="confirm" value="true"><TABLE>
<TR><TD nowrap align="center"><INPUT class=button3 name="userfile[]" type="file" size="40"></TD></TR>
<TR><TD nowrap align="center"><INPUT class=button3 name="userfile[]" type="file" size="40"></TD></TR>
<TR><TD nowrap align="center"><INPUT class=button3 name="userfile[]" type="file" size="40"></TD></TR>
<TR><TD nowrap align="center"><INPUT class=button3 name="userfile[]" type="file" size="40"></TD></TR>
<TR><TD nowrap align="center"><INPUT class=button3 name="userfile[]" type="file" size="40"></TD></TR>
</TABLE>
<BR><TABLE><TR><TD><INPUT class=button type="submit" value="+  Upload"></TD>
<TD><input class=button type="button" value="x  Cancel" onClick="javascript:location='http://www.example.parishcouncil.net/admin/admin_docs/index.php?action=list&dir=Public&order=name&srt=yes';">
</TD></TR></FORM><script language="JavaScript" type="text/javascript">
 <!--
function checkform ( form )
 {
if (/&/.test(form.userfile.value)) {
alert( \"Change the name of the file to remove the '&'.\" );
     form.userfile.focus();
     return false ;
   }
   return true ;
 }
 //-->
 </script></TABLE><BR>\n";

[Logic Ali]

First, use the error console and at least you'll see the syntax errors that prevent your code starting.

You are trying to test the group of fields as a single entity, which can't be done.

Just use this function:

function checkform( form )
{
  var inputs = form[ 'userfile[]' ],
      field,
      error = false;
 
  for( var i = 0; !error && ( field = inputs[ i ] ); i++ )
  {    
    if ( /&/.test( field.value ) ) 
    {
      error = true;
      alert( "Change the name of the file to remove the '&'." );
      setTimeout( function(){ field.focus() }, 10 );    
    }
  }

  return !error;
}

[howard-moore]

Thanks very much for this - worked a treat!