SQL Calculating The best salesman of the day

Hello Experts,

I have a table that contains information as follows:

SalesID, NumbSales, SalesDate

So: if salesman X sells 23 widgets on thursday, 30 widgets on friday, and 50 on Saturday
if salesman Y sell 14 widgets on Thursday, 33 widgets on friday and 42 widgets on saturday

my table looks like this:
rwid   SalesID   NumbSales   SalesDate

10   | 1         | 23              | '2012-07-06'|
11   | 2         | 14              | '2012-07-06'|
12   | 1         | 30              | '2012-07-07'|
13   | 2         | 33              | '2012-07-07'|
14   | 1         | 50              | '2012-07-08'|
15   | 2         | 42              | '2012-07-08'|


How can I get the salesmans ID who had the max sales for the day?

So I get:

10   | 1         | 23              | '2012-07-06'|
13   | 2         | 33              | '2012-07-07'|
14   | 1         | 50              | '2012-07-08'|

Thank you in advance!

-Fox