How to insert actual datetime with seconds into sql express database ?

Hi

On buttonclick i want to create a variable with startTime. Clicking the same button again should create a second variable with endTime.
Clicking the savebutton then should create a new row in my dataset and insert the two datetime variables.

I've created a MatchTable with following colums:

MatchID int (isIdentity)
PlayerName1 nvarchar(50)
PlayerName2 nvarchar(50)
PlayerPoints1 int
PlayerPoints2 int
MatchBegin datetime
MatchEnd datetime

I'm working with VC#Express

Thank you very much