creating Widget and adding event on IDL

PRO done_event, ev

WIDGET_CONTROL, ev.TOP, /DESTROY

PRINT, N_PARAMS()

END

PRO EX21

file = DIALOG_PICKFILE(PATH='E:\Image')

im = READ_IMAGE(file)

help, im

sz=SIZE(im,/DIMENSIONS)

wBase = WIDGET_BASE(/COLUMN)

wDraw = WIDGET_DRAW(wBase, XSIZE=sz[0], YSIZE=sz[1])

wButton = WIDGET_BUTTON(wBase, VALUE='Ganesh', EVENT_PRO = 'done_event')

WIDGET_CONTROL, wBase, /REALIZE

WIDGET_CONTROL, wDraw, GET_VALUE = index

WSET, index

TV, im

XMANAGER, 'EX21', wBase, /NO_BLOCK

END

PRO done_event, ev

WIDGET_CONTROL, ev.TOP, /DESTROY

PRINT, N_PARAMS()

END

PRO EX21

file = DIALOG_PICKFILE(PATH='E:\Image')

im = READ_IMAGE(file)

help, im

sz=SIZE(im,/DIMENSIONS)

wBase = WIDGET_BASE(/COLUMN)

wDraw = WIDGET_DRAW(wBase, XSIZE=sz[0], YSIZE=sz[1])

wButton = WIDGET_BUTTON(wBase, VALUE='Ganesh', EVENT_PRO = 'done_event')

WIDGET_CONTROL, wBase, /REALIZE

WIDGET_CONTROL, wDraw, GET_VALUE = index

WSET, index

TV, im

XMANAGER, 'EX21', wBase, /NO_BLOCK

END