Unable to use autoresponder form code in sidebar text widget

I've had this trouble before with a previous autoresponder.

I've found a much more affordable provider and would like to be able to use it on my blog.

It uses javascript, as many of them do, so I'm not sure it that is the hang up.

Here is the code:

<script language="JavaScript">
function checkSub(){
if (document.signup.email.value.indexOf('@', 0) == -1) {
alert("Please fill in your valid Email address.\nYour email should be in the following format: email@address.com")
document.signup.email.focus()
return false}
if (document.signup.fname.value == "") {
alert("Please fill in your First name.")
document.signup.fname.focus()
return false}
}</script><form action="http://1stautoresponders.com/cgi-bin/ar/optin.cgi" method="post" name="signup" onsubmit="return checkSub()"><input type=hidden name="action" value="addlead"><input type=hidden name="member" value="107"><input type=hidden name="auto" value="465"><input type=hidden name="thankyou" value=""><table border=0 cellspacing=0 cellpadding=2><tr><td><font size="2" face="arial, verdana">eMail address:</font></td><td><input type=text size=20 name="email"></td></tr><tr><td><font size="2" face="arial, verdana">First Name:</font></td><td><input type=text size=20 name="fname"></td></tr><tr><td></td><td align=center><input type="submit" value="Get My Newsletter"></td></tr></table></form>

Thanks for your help.

Tony Logue