How To Submit A Form On A Radio Click

I have an asp page with radio buttons and a combobox... when the user clicks
a radio button, I want the form to submit so I can execute the ASP code in
order to change the list shown in the combobox... I have 2 radiobuttons:

<input type="radio" name="terriprod" value="E">E
<input type="radio" name="terriprod" value="D">D

I have tried adding an OnClick event to each of the radio button...
<input type="radio" name="terriprod" value="D"
onclick="javascript:document.forms[0].submit();">D
but it does not work...

I have then tried to put each of the radio button into an anchor...
<a href="javascript:document.forms[0].submit();"><input type="radio"
name="terriprod" value="D"></a>D
but it does not work...

I have then tried to add to the onclick event a javascript function
<input type="radio" name="terriprod" value="D"
onclick="javascript:Verif(document.forms[0]);">D
and in the Verif function I try to submit the form but it does not work...

I have also tried:
I have then tried to add to the onclick event a javascript function
<input type="radio" name="terriprod" value="D" onclick="javascript:if
Verif(document.forms[0]) {document.forms[0].submit();};">D

But it does not work...