Record Locking

I have a program on a network were the database is on the sever. I installed the program on about three other station. Everything was doing find until today I got a 3343 error when I try to open a form that open the database in load. I'm Using MSAccess database that is password protected I know I need to use record locking but I’m not sure how.
The variable have dim out to represent the field names. When user click the button it update the database. there may be two to three user at a time updating the database.
Set DBS = OpenDatabase(Form1.Text1)
Set dbs1 = DBS.OpenRecordset("timehold")
dbs1.AddNew
dbs1(m) = txtLateS
dbs1(l) = txtINE
dbs1(K) = txtLate
dbs1(j) = txtIDTH
dbs1(c) = lblFirstN
dbs1(b) = lblLastN
dbs1(a) = lblMiddleN
dbs1(d) = txtStart
dbs1(e) = txtStartDate
dbs1(f) = Text8
dbs1(g) = Text9
dbs1(h) = txtpassword
dbs1.Update
dbs1.Close
DBS.Close