xquery version "1.0";

(: This function take a string as input and return it surrounded by stars '*' :)
declare function addStars($str as xs:string) as xs:string
{
   fn:concat("***", $str, "***")
};



(: The script make use of its function :)
fn:concat( addStars("some input string"), "  ", addStars("some other string"))