Add a blank entry to a dropdownlist filled by a dataset

I'm not sure how to add a blank listitem to the top of a dropdownlist that is filled with a strongly typed dataset. Here is what I am using to fill the dropdownlist.

Tried adding the following to the top but was overwritten.

ddlCategories.Items.Add(new ListItem("", "Select Category"));
dsForumCategoryTableAdapters.ForumCategoriesTableAdapter categoryTA = new dsForumCategoryTableAdapters.ForumCategoriesTableAdapter();
dsForumCategory.ForumCategoriesDataTable categoryDT = categoryTA.GetData();
ddlCategories.DataSource = categoryDT;
ddlCategories.DataValueField = categoryDT.Columns["CategoryID"].ToString();
ddlCategories.DataTextField = categoryDT.Columns["Title"].ToString();

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Daniel ReynoldsSoftware Applications Developer / IntegratorCommented:
have you tried adding the item after you have bound the data?

Another option is to create the query in a stored procedure that adds the dummy record "Select a Category" to the resultset.
tristamaneAuthor Commented:
The snippet attached works but I am using the CategoryID as the value and it requires an int value otherwise throws error.

System.ArgumentException: Input string was not in a correct format.Couldn't store <> in CategoryID Column.  Expected type is Int32.

Any suggestions to get around it? I need a blank value for client side validation.

DataRow row = categoryDT.NewRow();
row["CategoryID"] = "0";
row["ParentID"] = "0";
row["Title"] = "";
categoryDT.Rows.InsertAt(row, 0);

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Daniel ReynoldsSoftware Applications Developer / IntegratorCommented:
Can you give it a negative value , say -1?
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tristamaneAuthor Commented:
That didn't work. The RequiredFieldValidator is not firing. I'm guessing the only way around is to create a CustomValidator with client side validation.
Saqib KhanSenior DeveloperCommented:

No need to add a dummy value via database commands.

vendorsLst.Items.Insert(0, New ListItem("Choose Vendor"))
where vendorsLst is name of control, 0 is the first position and replace "choose vendor" with your value.

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tristamaneAuthor Commented:
Eggsalad, the following did the trick.
ddlCategories.Items.Insert(0, new ListItem("Select Category", ""));

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