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)';