DataSet.DataTable.FindBy() returns <undefined value>

Hi!

I have a table "USER" (in SQL database) with primary key "USR_ID" and
DataSet filled with that table.

When I call dataSet.USER.findByUSR_ID(x) it returns <undefined value>.

What is the problem?

<code>
private void Page_Load(...)
{
checkBox1.checked = IsUser();
}

public bool IsUser()
{
Decimal x = 1;
DataRow temp = dataSet3.DP_USER.FindByUSR_ID(x);

if (temp != null)
return true;
else
return false;
}
</code>

If I wrote to little of code to solve the problem, say what is missing.

Best regards, Dejan