You could swap the function calls around the other way assuming they are independent of one another.
Code:
<div id="formbuttons"><input class="buttonsubmit" id="btnsubmit" name="btnsubmit" onclick="wrs_trackclick('DCS.dcsuri=formsubmit', 'WT.ti=form submit','WT.dl=24'); return formvalidate(); " type="submit" value="Send"/> </div>
This is an example of why it is better to use event listeners in JavaScript rather than event handlers - you would have been able to add a second submit listener without needing to update any of the already existing code.