Sc_redir modal in a pop up, not in a tab

MAIN_APP redirects to app1 which immediately redirects to app2.
so user effectively only sees mani_app redirecting to app2.
i wrote below redir code in on change field ajax in mani_app :
sc_redir(app1,‘glob_rate=$rate’;“modal”,60,70);
and same code in app1 sc_redir(app2,‘glob_rate=$rate’;“modal”,60,70);

my problem is its redirecting in seperate tab, i want a small window to pop up in same screen.

any guidance please?

ok, i got it
in main_app i wrote i used sc_redir(app_name,’’,modal) ;
in app1 i just wrote sc+redir(app2);