The HTML variable TYPEDRILL contains the names of the files that are the targets for the values of the variable TYPE.

if type="Corn" then
typedrill="HREF='type1_body.html'";
else if type="Rice" then
typedrill="HREF='type2_body.html'";
else if type="Wheat" then
typedrill="HREF='type3_body.html'";
run;