C#

<br />
System.Drawing.Point pt = this.dgUnAllocatedOrders.PointToClient(Cursor.Position); <br />
DataGrid.HitTestInfo hti = this.dgUnAllocatedOrders.HitTest(pt); <br />
if(hti.Type == DataGrid.HitTestType.RowHeader) <br />
{ <br />
Yourform alloc=new Yourform();<br />
alloc.ShowDialog();<br />
}

[DllImport("gdi32.dll")]
static extern int GetDeviceCaps(IntPtr hdc, int nIndex);

int WU_LOGPIXELSX = 88;
int WU_LOGPIXELSY = 90;
int TwipsPerInch  = 1440;

private int PixelsToTwips(int pixels, bool bIsHorizonal)
{
    int twips;
    Graphics g = Graphics.FromHwnd(IntPtr.Zero);
    IntPtr hdc = g.GetHdc();
    int pixelsPerInch;
    if(bIsHorizonal)
        pixelsPerInch = GetDeviceCaps(hdc, WU_LOGPIXELSX);
    else
        pixelsPerInch = GetDeviceCaps(hdc, WU_LOGPIXELSY);
    g.ReleaseHdc(hdc);
    double numInches = pixels/pixelsPerInch;
    twips = (int)(numInches * TwipsPerInch);
    return twips;
}

public class myGrid: System.Windows.Forms.DataGrid
{

	protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
	{
		if(keyData == Keys.Tab)
		{
			this.CurrentCell = new DataGridCell
                                 (this.CurrentCell.RowNumber,1);
		}
		return base.ProcessCmdKey (ref msg, keyData);
	}

}