DataRow array NullReferenceException help!!

[laic]

I have a question about accessing a datarow array which result to be "Object reference not set to an instance of an object."

Below is my code in brief:
//****************************************************
private DataTable DT;
private DataRow[] DR;
private Repeater rep;
protected System.Web.UI.WebControls.Label Label1;

private DataRow[] SortRow(string year, string month, string day)
{
//I have already made the SQL connection and successfully
//show my data in a datagrid.
return DT.Select("Year='" + year + "' AND Month='" + month + "' AND Day = '" + day "'";
}

private void RepeaterBind()
{
DR = SortRow("2005", "04", "26");
rep.DataSource = DR;
rep.DataBind();
}

private void showRow()
{
for(int i = 0; i < DR.length; i++)
Label1.text = DR["Purpose"]; //NullReferenceException
//just to check if the data from SortRow are still there.
}
//****************************************************

I understand that when I declare DataRow = DR, I did not initialize it and give an array size.
However, even if I did give it a size, and initilaize, it will not have an error, but the data are not in the DR.
It seems that data in DR only live in that RepeaterBind() block. Once out of that block, the reference is gone.

Is there anyway to fix this thing?? or ??
I am not sure if this has anything to do with deep copy array.
Please help me out here, I've stuck on this issue for
4 days already.

Laic