URL field to a picture with link (button)

[cakissimo]

Hello,

I'm newbie and i don't speak english very well, sorry for this.

When a member complete the form, I would like the link appears as a clickable button ... it seems stupid but I can not do it, sorry.

This button is not an image upload by the member at the thread posting , it's just a "participate" button link (for a forum dedicated to referencing  contests..to win price)

I have try this and lot other things in "display format" but without success:
<a href="{VALUE}"><img src="images/image-perso/participer.png"</a>

See pictures if it was not understandable


Thank you for this wonderful tool, it's very useful.