Web page form not downloading Download.aspx

Trying to integrate LogMeIn Rescue into our web site.

I'm using the standard HTML

<form name="channel1383xxxxx" action="https://secure.logmeinrescue.com/Customer/Download.aspx" onsubmit="return checkForName()" method="post">
<input type="text" id="support_name" placeholder="Enter your name" />
<p><input type="submit" id="submit-btn" value="Start Remote Connection" /></p>
<input type="hidden" id="EntryID" value="1383xxxxx" />
<input type="hidden" id="tracking0" maxlength="64" />
<input type="hidden" id="language" maxlength="5" />
</form>

But instead of downloading and running Download.aspx  I get a temp page saying I have to download the applet, then end up on

https://secure.logmeinrescue.com/Customer/Entry.aspx

Any ideas?

Hosting on Windows IIS & Plesk.

TIA