pass value in main form doesn't work

[ahmedtharwat19]

hi everybody
i tied to pass value from subform to main form but it not work with me!!

I need Send [total_item_value] from subform to field [total_values] in main form

it work when i save the record in main form
i need to see the total_value in main for after each record in subform

ex:

subform:

Item_id | qty | item_price | item_value
101 | 8 | 10 L.e | 80 L.e
102 | 15 | 25 L.e |375 L.e

MAINFORM

total_value = (80+375)=455


i need when i add record in subform i see the total_value change in mainform after each move

thank you for advance

[zmbd]

We usually ask that you show your work.
What have you tried already to do this?