Web Forms :: How To Show Multiple Selected Items Of A Listbox

I had used listbox control with multiple selection mode. I stored id with comma delimiter in database.

e.g.

1. List Item One.
2. List Item Two.
3. List Item Three.
4. List Item Four.
5. List Item Five.
6. List Item Six.

Suppose user select item 2, 4 & 6. So I will store it as a 2,4,6 in database. This will work fine.

Now in editing I have to shows selection-bar for item 2, item 4 & item 6. So I had typed below source.

string strData ="2,4,6"
if(strData != null)
{
char[] separator = new char[] { ',' };
string[] strSplitArr = strData.Split(separator);
int x = 0;
for (x = 0; x < strSplitArr.Length; x++)
{
// lstWDef_PurchasesEdit.Items[x].Selected = true;
lstWDef_PurchasesEdit.SelectedValue = strSplitArr[x].ToString();
}
}

But with this statement I got only last item id as a selected item with selectionbar. In our example 2,4,6 only item whoseid is 5 got as a selected item.

if i use

for (x = 0; x < strSplitArr.Length; x++)
{
if (lstWDef_PurchasesEdit.Items[x].Value == strSplitArr[x])
{
lstWDef_PurchasesEdit.Items[x].Selected = true;
}
}

if the selected items are serial like 2,3,4 then it is displaying correctly..

if items are 2,4,6 then it is not selecting the items of listbox properly.

Is anybody guide me how to make item 2, item 4, item 5 as a selected item ?