Pass Childwindow textbox Value To Parent Window gridview

Question

I used java script to open a new window(child) when user clicks on button from parent window.
 
On new window(child), I have text box and button, I need to get the value of the text box and pass to parent window gridview when user clicks on button, while closing the child window, I need display my value gridview of the parent window , how can I do that?
 
1- parent window has button, clicked child window opened
2- child window has text box and button, when button clicked, get the value of the text box and pass to parent window and close child window.
3- and display the child windows text box value to gridview in parent window.
 
I hope it is clear