conditions statment on htmltable

Question

hi everyone ,

 

i want to ask  a, first i have a listbox then left and right side have a two button 

 

when i search two dates for ex from 2010 to 2015 , these years inserting  listbox  2010,2011,2012,2013,2014,2015, 

 

then when i use button  line 27 and 29 if im back to 2010 then again click button i have a get blank page, so how can i conditions this statment ? 

 

thanks  

 

1- htmlTr = new TableRow();

2-htmlTable.Rows.Add(htmlTr);

3-

4-var lstYearList = new ListBox();

5-lstYearList.Attributes.Add("style", "Overflow:hidden");

6-lstYearList.Height = 20;

7-lstYearList.CssClass = "dev-year-list";

8-int minYear = ConvertLib.ToInt(searchConds.Year2, 2007);

9-int maxYear = ConvertLib.ToInt(searchConds.Year, DateTime.Today.Year);

10-var loopYear = minYear;

11-for (; loopYear <= maxYear; loopYear++)

12-{

13-lstYearList.Items.Add(new ListItem(loopYear.ToString(), loopYear.ToString()));

14-}

15-

16-if (specYear.HasValue)

17-{

18-WebUtilBox.SetListControlSelected(specYear.Value.ToString(), lstYearList);

19-}

20-else

21-{

22-WebUtilBox.SetListControlSelected(maxYear.ToString(), lstYearList);

23-}

24-

25-htmlTh = new TableHeaderCell();

26-htmlTh.CssClass = "year";

27-htmlTh.Text += string.Format("<a href='javascript:;' class='prev dev-prev-year' onclick='prevYear();'></a>");

28-htmlTh.Text += WebUtilBox.ToHtmlText(lstYearList);

29-htmlTh.Text += string.Format("<a href='javascript:;' class='next dev-next-year' onclick='nextYear();'></a>");

30-htmlTr.Cells.Add(htmlTh);