Checking the database value null

if (OrderLinesDs.Tables[0].Rows[0]["Billing_FAX"]!=null)
{
txtFax.Text="";
}
else
{
txtFax.Text=(string)OrderLinesDs.Tables[0].Rows[0]["Billing_FAX"];
}
>>above code checking both the condition.what is the best solutions on this

Help help

Here's one way:

Code:

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    if (Convert.IsDBNull(reader["FirstName"])) {
        Response.Write("No soup for you!");
    }

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