Invoke required field validator through javascript

I have a non standard submit button in my ASP.NET form along the lines of.

<a class="button" href="#" onclick="this.blur();SubmitForm();"><span>Submit</span></a>

Due to this, my required field validator is not being invoked on the client side. How can the required field validator be invoked through Javascript?

Alternatively is there a better way to accomplish what I am attempting to do?