Validate Multiple Select Box 1

TanTrazz · Nov 13, 2007

Hi All,

Does someone know how to validate an multiple selectbox?

I want to max the selection to 4. When they select the fifth they have to get an message which tell them they can only select 4 options.

<form method="_GET" action="post.asp" name="form1">
<select name="ckb" size="20" multiple="multiple">
<option>Value1</option>
<option>Value2</option>
<option>Value3</option>
<option>Value4</option>
<option>Value5</option>
<option>Value6</option>
<option>Value7</option>
</select>
</form>

Thanks in advance.

TanTrazz

kaht · Nov 13, 2007

This code will not unselect any option after 4. To get that kind of functionality it's going to start to get messy. However, this will perform the check you're wanting:

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "[URL unfurl="true"]http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">[/URL]
<html xmlns="[URL unfurl="true"]http://www.w3.org/1999/xhtml">[/URL]
<head>
<title>test</title>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<script type="text/javascript">

function howMany(selObj) {
   var totalChecked = 0;
   for (i = 0; i < selObj.options.length; i++) {
      if (selObj.options[i].selected) {
         totalChecked++;
      }
   }
   if (totalChecked > 4) {
      alert("You can't check more than 4 options");
   }
}

</script>
<style type="text/css"></style>
</head>
<body>

<select name="ckb" size="20" multiple="multiple" onchange="howMany(this)">
   <option>Value1</option>
   <option>Value2</option>
   <option>Value3</option>
   <option>Value4</option>
   <option>Value5</option>
   <option>Value6</option>
   <option>Value7</option>
</select>

</body>
</html>

-kaht

Lisa, if you don't like your job you don't strike. You just go in every day and do it really half-assed. That's the American way. - Homer Simpson
[small] <. bites again.[/small]

TanTrazz · Nov 13, 2007

Hi Kaht,

Thanks for the code it works fine!!

TanTrazz

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Validate Multiple Select Box 1

TanTrazz

Programmer

kaht

Programmer

TanTrazz

Programmer

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