I have a form on a landing page. I am giving the lead the ability to multi-select for a particular field but I want to limit the amount of values that they can select. The field has 40 values but I want to limit them to just pick 3. Is there a way that I can do this?
Before I answer, you're using the true <select multiple> type (not checkboxes)?
Just put the code from the JS pane inside a <script>. On a Marketo LP, put it right before the closing </body>. If you're using the embed code, put it anywhere after the embed code.