4GL INPUT statement problem

We have an input statement in which we want to prevent modifications to certain rows (based upon the value of one of its fields), but we still must display them all (and we cannot re-order it to put unmodifiable rows at the bottom). I am able to skip a row when the user is scrolling down, BUT when they scroll up, I can't seem to skip the unmodifiable row. Is this impossible? Do I really have to let them into an unmodifiable row and give an error message when they do try to modify it? (I know you can determine the direction of scrolling with fgl_lastkey(), but the problem is there is no way to specify that I want to put them on a field in the row above where they're at now.) Thanks in advance, - Dan Wright #include <StdDisclaimers.h>