Add a number to string

in my code below i want to add that if reorderthreshold is 2 away from the quanity to make the row red? how would i code that below?
Protected Sub OnRowDataBound(sender As Object, e As GridViewRowEventArgs) sqlthreshold.selectcommand = "select quantity,reorderthreshold from hardware" Dim dv As DataView = CType(sqlthreshold.select(DataSourceSelectArguments.Empty), DataView) If e.Row.RowType = DataControlRowType.DataRow Then If dv.Count > 0 Then Dim i As Integer = 0 Dim dr As DataRow = dv.ToTable().Rows.Item(e.Row.RowIndex) Session("quantity") = dr.Item(0).ToString Session("reorderthreshold") = dr.Item(1).ToString End If If Integer.Parse(Session("quantity").ToString) > Integer.Parse(Session("reorderthreshold").ToString) Then For ccount As I ...