Show each dimension sum amt by last date

[timml_hsu]

Hi, All

We have data as below:

SEQ	USER	BUY_DATE	AMT
W01	User 1	2018/06/03	100
W02	User 2	2018/06/03	100
W03	User 3	2018/06/03	100
W04	User 4	2018/06/03	100
W05	User 5	2018/06/03	100
W06	User 1	2018/07/04	50
W07	User 1	2018/07/04	50
W08	User 2	2018/07/04	50
W09	User 4	2018/07/04	50

We want to show each user last buy date & last buy amt.
We want to show each user last buy date & buy amt at last buy date.
as below :

User1, 2018/7/4, 100
User2, 2018/7/4, 50
User3, 2018/6/3, 100
User4, 2018/7/4, 50
User5, 2018/6/3, 100

We have tried.
Dimension: USER
Last Buy Date expression: MaxString(BUY_DATE)
Last Buy Amt expression: SUM({<BUY_DATE = {"$(=MaxString(BUY_DATE))"}>} AMT)

USER	Last Buy Date	Last Buy Amt
User 1	2018/7/4	100
User 2	2018/7/4	50
User 3	2018/6/3	0
User 4	2018/7/4	50
User 5	2018/6/3	0

but it only show last date, miss user3 & user5 last amt.
How could we to do, thanks 

[Anil_Babu_Samineni]

Perhaps simply like

Dimension : User

Expression:

Max(BUY_DATE)

SUM(AMT)

[timml_hsu]

Sorry,  my mistake.

We want to show each user last buy date & buy amt at last buy date.

[Anil_Babu_Samineni]

Could you please modify the output result also

[timml_hsu]

Hi, Anil_Babu_Samineni

thanks your reply
We have modified question.

We want display:

User1, 2018/7/4, 100
User2, 2018/7/4, 50
User3, 2018/6/3, 100
User4, 2018/7/4, 50
User5, 2018/6/3, 100

But, use SUM({<BUY_DATE = {"$(=MaxString(BUY_DATE))"}>} AMT) 
qlikview  show as below:

USER	Last Buy Date	Last Buy Amt
User 1	2018/7/4	100
User 2	2018/7/4	50
User 3	2018/6/3	0
User 4	2018/7/4	50
User 5	2018/6/3	0