Sjg:grid refresh of parent window from modal window

[fea jabi]

1. I have a web page which is having a <sjg:grid> 
 
2. From this webpage I open a modal window which has a link to update the 
parent window grid information. 
 
3. Once the modal window is done with it's work and closes. how to trigger the 
refresh the parent window grid ?
 
Need help with this please.