Hi Santhosh

Refer the following example

.Mr Rahul,an Admin Executive took advance of Rs 500 for purchase of items for office toilet He purchased items for  Rs 350 as per bill submitted to him of Ghai Store and duly returned balance Rs 150.

-a-

Rahul Imprest  a/c  Dr  500

   To  Cash a/c/Petty Cash A/c 500

(Cash kept with Employee is called Imprest A/c 

Office Expense  a/c Dr  350   

   To Rahul Imprest  a/c 350

Cash  a/c  Dr 150

  To  Rahul Imprest  a/c 150

-ea-

Note

 In some companies,for petty cas concept of IOU is followed

Learn here

http://teachoo.com/89/1247/Petty-Cash-Procedure-in-Companies-for-Cashiers/category/Cash-Handling-and-Reconcilation-Process/