I\'m trying to get Google Analytics Code to work on the thank-you page after customer has filled in the contact form and I\'ve tried putting it in the thank-you page which is in
It sounds like you're trying to add it using the "Visual" view, which formats whatever you put in into paragraphs, etc.
Try switching to "HTML" view (the tab is at the top right of the input box) and add it there - hopefully that should allow you to add it without converting it!
Edit: As per my comments below, I made a mistake - it seems even the HTML tab adds some degree of formatting.
In this case, you may find some use with this plugin:
http://wordpress.org/extend/plugins/raw-html/
This allows you to displable to auto formatting on a per-post basis. So on that specific page you could turn off the autoformatting simply to allow you to add that Analytics snippet.
The only other way I can think off offhand would be to write a custom page_template just for that thankyou page and add it to there. Instructions are here: http://codex.wordpress.org/Pages#Creating_Your_Own_Page_Templates