Help required for DataGrid in asp.net

[Jothi]

I want to retreive columnheader value which bound for sql in datagrid in asp.net.
I have used the following code for retreiving header text.
dim i as integer
dim j as integer
j=DataGrid1.Columns.count-2

for i = 1 to j

Response.write(DataGrid1.Columns.item(i).HeaderText)
Response.write(DataGrid1.DataGridItem.Items(i).ItemType)
Next
But it is showing an error at "Response.write(DataGrid1.DataGridItem.Items(i).ItemType)"

I have also tried with Response.write(DataGrid1.columns.Items(i).DataField).But nothing is helpful.How can i get the bound value from Datagrid columns.Thanks in advance.Please help me.