removing the loops using Linq Query

Dim dtUsers As New System.Data.DataTable
                   Dim dsUserID As New System.Data.DataSet
                   Dim cbPRRep As New comobox()
                   For Each druser As DataRow In dtUsers.Rows
                       dsUserID = Security.GetUserDataById(druser("UserID"))
                       For Each rw As DataRow In dsUserID.Tables(0).Rows
                           Me.cbPRRep.AddEmptyItem(rw("UserId"))
                           Exit For
                       Next
                   Next
                   Me.cbPRRep.SelectedIndex = -1