Input type="image" asp.net

i am trying to make an image a submit button. I know in asp this works if you do input type="image" it doesnt seem to submit the form when i try this in asp.NET.
Any ideas why?
What am i doing wrong?

Use the Image Button from the Toolbox.

Have you placed it in your form correctly?

I think i did.
i made the form runat="server".
My question is how do i tell it to submit the form?
When its clicked it calls the onClick event in the .vb code so how do i submit the form at that point?

The concept of submission is somewhat redundant with the use of server side controls. You can simply place the code you want to run (when the form is submitted) in the image's click event (codebehind)

I am trying to submit to a page that already exists, so i cant really do that.
So what you are telling me is that in .NET there is no way to make an image a submit button????

There is. In this case, you can place "document.form.submit()" in the image's onClick event.