fixed text for non-linear

fdt.tcl

@@ -81,7 +81,8 @@ proc fdt:dialog { w tclstartupfile } {
     label       $w.registration.struct.lb -text "Main structural image"
     TitleFrame  $w.registration.struct.tf -text "Main structural image" 
     frame       $w.registration.nonlin
-    checkbutton $w.registration.nonlin.yn -variable registration(nonlin_yn) -text "Non-betted structural" -command "registration_packframe $w"
+    checkbutton $w.registration.nonlin.yn -variable registration(nonlin_yn) -text "Nonlinear" -command "registration_packframe $w"
+    label       $w.registration.nonlin.lb -text "Non-betted structural image"
     FileEntry   $w.registration.nonlin.file -textvariable registration(nonlin_image) -filetypes IMAGE 
 
 
@@ -120,8 +121,8 @@ proc fdt:dialog { w tclstartupfile } {
        pack forget $w.registration.struct.yn $w.registration.struct.tf $w.registration.struct.yn $w.registration.struct.lb $w.registration.nonlin.yn $w.registration.nonlin.file
        pack forget $w.registration.standard.yn $w.registration.standard.tf $w.registration.standard.yn $w.registration.standard.lb
        if { $registration(struct_yn) } { pack $w.registration.struct.yn $w.registration.struct.tf -side left -anchor w } else { pack $w.registration.struct.yn  $w.registration.struct.lb -side left -anchor w}
-       if { $registration(struct_yn) } { pack $w.registration.nonlin.yn -side left }
-       if { $registration(struct_yn) && $registration(nonlin_yn) } { pack $w.registration.nonlin.file -side left }
+       if { $registration(struct_yn) } { pack $w.registration.nonlin.yn -side top -anchor w }
+       if { $registration(struct_yn) && $registration(nonlin_yn) } { pack $w.registration.nonlin.lb $w.registration.nonlin.file -side left }
        if { $registration(standard_yn) } { pack $w.registration.standard.yn $w.registration.standard.tf -side left -anchor w } else { pack $w.registration.standard.yn  $w.registration.standard.lb -side left -anchor w}
     }