WBUILD is a SAS macro. The double percent sign that precedes WBUILD is necessary to prevent PROC PMENU from expecting a field number to follow. The field numbers %1, %2, and %3 equate to the values specified by the user with the radio boxes. The field number @1 equates to the search value that the user enters. See "How the WBUILD Macro Works" .
       dialog d1 '%%wbuild(%1,%2,@1,%3)';