Custom image links/rowcommands in a gridviews header?

[jobs]

two questions..

1. I'm having a problems changing the headerimageurl on the fly in the
code behind. In rowcreated, I have this code:

If e.Row.RowType = DataControlRowType.Header Then
If grid.EditIndex <> -1 Then
grid.Columns(0).HeaderImageUrl = "../App_Themes/
WinXP_Silver/Images/cancel.gif"

End If

I'm trying to use position 0,0 of the grid for NEW and Cancel.

but it causes error:

Column 'JobName' does not belong to table DefaultView.

JoName is the second column in the grid, the first (0), is buttonfield
that takes the row into editmode. The above errors is not happening in
that block of code.

Is it possible to change the headerimageUrl . If so where? and how?

2. Provided that it is, any way to use header images as command links
in my gridview?