Thanks for the aswers guys!
1. Guest: The image type does the same thing as the submit (it submits the form...so...). The bracket is wrong here but the HTML do not count the diference.
2. Oldhack: I did what you said but: RED LIGHT! hehehe
I think that the problem is about the aspx page configuration or something. For me, the only thing this form is doing is refresh the page (crazy!). I am using Visual Studio 2010 with asp.net and C#.
More ideas????

Mark Garret