Slider to Edit in call back does not work

I do have a slider in my GUI . The value in the edit textbox doesn't work when the slider is moved but the slider updates its position according to the textbox value.. can anyone suggest a solution for this?

// Edit box to slider works in edit call back

 textValue = str2double( get(hObject,'String') );
 set(handles.Iapp,'Value',textValue);

//slider to editbox in slider call back -does not work

 iext = num2str(get(hObject,'Value'));
 set(handles.edit1,'String',iext);