WHen submitting form, outlook popsup

In Dreamweaver MX, i want to create a form, where the information is sent to an email address after u hit submit. I have made the form itself, and done the proper coding, but when i hit submit,, Outlook express pops up and displays the email that i want to send. I am really confused and cant seem to figure out what the problem is, i just want it automatically to be sent to the specified email address. Also i would like a page saying thank you for submitting your form, etc, etc, etc. I would really like help on this, its for a school project and its due in two days and i'm STUMPED!! thanks Tony G