vb.net crosshair cursor...


i have the following code for drawing a crosshair cursor & it works:

'Custom cursor
'Declare bitmap
Dim bm As New Bitmap(64, 64)
'Declare graphics
Dim g As Graphics = Graphics.FromImage(bm)
'Clear the graphics
'Declare cursor pen and set colr + width
Dim myCursorPen As Pen = New Pen(Color.White, 2)
'Draw cross hair
g.DrawLine(myCursorPen, 32, 0, 32, 64)
g.DrawLine(myCursorPen, 0, 32, 64, 32)
'Dispose the graphics
'Declare a cursor object
Dim cur As New Cursor(bm.GetHicon)
'Set the cursor object
Me.Cursor = cur

the problem is that its 64*64 and i cannot increase it. how can make
it to 500*500?? if i try it does not work!

any ideas?