@coroico: fieldset {border: none} did the trick. Thanks
@mrhaw: FYI I use xhtml transitional.
@BobRay: I don’t know if I can use a template with AS to replace <fieldset> with <div>.
Would like to know if using a template is possible, otherwise it would mean the snippetcode must be hacked to get rid of the <fieldset> tags.
The ’problem’ with fieldset {border: none} is that IE and FF now use a different margin. Since the search field should be lined up to the left with the logo of my site, I’ll have to program two different left margins for IE and FF. With <div> instead of <fieldset> that would not be necessary.