creating duplicate record on page refreshe

Hi All,

 

In our project when clicking on a button I am generating a unique id which starts a transaction.

In the started transaction a new window opens (using window.open()) on clicking of a button, saving of which I need to refresh the page where in I generating the unique id. After refreshing it is generating one more transaction.

 

How to avoid executing the code by refreshing the page?

 

 

Thanks in Advance,

Laxmi Narayana.