Sending HTML content via an email contact form

I currently have an email contact form that uses cdonts.

I would like to modify this form so that HTML content can be included, such as a hyperlink to a web address. Currently a web address would appear as plain text.

Is it possible to do this, and if so, can anyone tell me what changes would need making to the script in order to achieve this?

Thanks

Have a look at this

4GuysFromRolla.com - Sending HTML-Formatted Email

Just be carefull you don't open it up to injection vunrabilities