This part is an assignment, not a comparison, replace = with ==:
JavaScript Code:
if(document.getElementById('hGo').value="T")
This would cause the form to always submit. Is that what you mean by "having problems?".
I would also suggest that you switch from using the GET method to POST when sending the text for validation as it'll probably get around a few problems with url encoding.
And I hope you also perform this check on the serverside, just in case JavaScript isn't enabled on the client, or someone tries to evade it.
