problems with slice viewer

Hi,

I am just trying to overlay a subject's zmap that I created in dparsfa that reflects the correlations among various ROIs over a structural image using slice viewe but get the following error message:

Warning: image_toolbox not valid
> In rest_sliceviewer>InitControls at 917
In rest_sliceviewer at 68
In rest_sliceviewer at 32
In rest_Utilities_gui>btnSliceViewer_Callback at 98
In gui_mainfcn at 96
In rest_Utilities_gui at 28
??? Error using ==> rest_sliceviewer>AddOverlay at 2903
You must install image_toolbox first!

Error in ==> rest_sliceviewer>SetView_Orthogonal at 1445
theSagittalImg =AddOverlay('Sagittal' ,AConfig, theSagittalImg,theMagnifyCoefficient);

Error in ==> rest_sliceviewer>SetImage at 1361
Result =SetView_Orthogonal(AConfig);

Error in ==> rest_sliceviewer at 452
REST_SliceViewer_Cfg.Config(theCardinal)
=SetImage(REST_SliceViewer_Cfg.Config(theCardinal));

Error in ==> rest_sliceviewer at 471
rest_sliceviewer('ChangeOverlay', AFigHandle);

??? Error while evaluating uicontrol Callback