You could change the color of a label to make it look unavailable (gray maybe) and set the readonly flag of a text box <input name="" type="text" readonly="true"> Code (html4strict):
try <input name="" type="text" readonly> Code (markup): or <input name="" type="text" readonly="readonly"> Code (markup): depending on your doctype and check http://www.w3schools.com/tags/tag_input.asp
This is how you become very unpopular in a short space of time. There are a large number of forums here, try link exchange and don't hijack other people's threads.
Next time there's a post like that, (as was recently suggested to me) click the little exclaimation mark icon on the upper right-hand corner of the post to flag it so the moderators can move the post. BTW, this thread shouldn't be in the PHP forum?!
lost is asking how to disable textboxes, which seems fitting in the HTML & Website Design forum. Though I have to admit that when I read the topic, I thought the use of "desensitize" was going to be about sanitizing form submit data for special characters. In that case, this thread would've been best in the PHP forum. So maybe we thinking the same thing.