Refreshing Control Inside the Form

I have a form containing grid control, such control is bound to a certain table. I also placed a textbox control within the same form.

The scenario goes like this; if the user inputs a value in the texbox control, the value will be saved to the table where the grid control is bound to.

I have placed the updating of table codes in the OnValidate trigger of the textbox and everything worked well. The data was saved in the table.

In order to update the controls inside the form, I used the UPDATECONTROLS function (placed also inside the OnValidate trigger)

The grid content is supposed to be updated also right after the updating of the table, but the value which is just added by the user can't be seen from the grid control. But when I issue the UPDATECONTROLS function in the OnPush trigger of a command button control, the grid value updates.

Why is that the grid control can't be updated (refreshed) when i'm issuing the UPDATECONTROLS function inside the OnValidate trigger of a textbox?

Pls. help..