Insert/Update SP

[geo039]

Background:
I'm a beginner developer learning when to use the app and when to use the DB to execute what I need. I have two tables in separate databases with employee data. I need to set my asp.net application variable to today so a sp would run based on that.

Question:
The sp needs to check for empid in Table B. If exists update based on info in Table A if not found insert from Table A.

I have this update statement

UPDATE  dbo.employee 
SET full_name = t.full_name, cost_center = t.cdcstcntr,
    cost_center_desc=t.desccstcntr, job_title=t.job_title,
    supervisor=t.supervisor_name
FROM dbo.v_WQTimeEmployees as t RIGHT OUTER JOIN 
    dbo.employee ON t.empUserID = dbo.employee.NTUserID
WHERE t.empUserID = dbo.employee.NTUserID 
    AND (dbo.employee.manual IS NULL or dbo.employee.manual=0)

I just don't know how to say in SQL, if empuserid found update if not insert.

Thanks for your assistance.

[Rune Bivrin]

UPDATE  dbo.employee 
SET full_name = t.full_name, cost_center = t.cdcstcntr,
    cost_center_desc=t.desccstcntr, job_title=t.job_title,
    supervisor=t.supervisor_name
FROM dbo.employee e
JOIN  dbo.v_WQTimeEmployees as t 
 ON t.empUserID = e.NTUserID

INSERT INTO dbo.employee (NTUserID, full_name, cost_center, cost_center_desc, job_title, supervisor)
SELECT t.empUserID, t.full_name, t.cdcstcntr,
    t.desccstcntr, t.job_title,
    t.supervisor_name
FROM dbo.v_WQTimeEmployees as t 
WHERE NOT EXISTS (SELECT * 
                             FROM dbo.Employee e 
                             WHERE e.NTUserID = t.empUserID)