After successfully integrated CCAvenue Payment gateway response message return 404 error,
Form :
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<input type="hidden" name="tid" id="tid" readonly />
<input type="hidden" name="merchant_id" value="1234"/>
<input type="hidden" name="order_id" value="123654789"/>
<input type="hidden" name="currency" value="INR"/>
<input type="hidden" name="redirect_url" value="abc.com/ccavResponseHandler.php"/>
<input type="hidden" name="cancel_url" value="abc.com/ccavResponseHandler.php"/>
<inputtype="hidden" name="language" value="EN"/>
<button type="submit" class="btn btn-default" id="pass">Pay</button>
</div>
</div>