Thread: normals for triangle strips (oGL)

where do you specify normals when drawing triangle strips? what i mean is that with 4 verticies i draw 2 triangles having (potentially) 2 different normals. if i have 4 calls to glVertex(), at what point do i specify the normal of the second triangle.

ex)

Code:

glNormal( .... ); // normal of first triangle

glVertex( ... ); // vertex 1
glVertex( ... ); // vertex 2
glVertex( ... ); // vertex 3
glVertex( ... ); // vertex 4

vertices 1,2,3 make up a triangle with one normal and 2,3,4 are a triangle with a different normal. at which line can i call glNormal() to specify the second normal so that both triangles have their own distinct normal??