Disable website field in comments??

I want to disable URL in comments, i mean that i want that website to have url field in comment but i dont want it to link with author name. It should be taken as simple text to simply trashed. i dont want to remove url field.
one more thing that to disable html in coment field i added // in kses.php in from of allowed html tags. is this method acurate??

Thanks for reading and thanks twice if you reply