How could i use negative float values in OpenGL functions?

Next line works fine:
invoke glTranslatef,0.0f,0.0f,-5.0f

But if i use variable then negative value does not work:

z GLfloat -5.0f

invoke glTranslatef,0.0f,0.0f,z

Maybe i should use another variable type than GLfloat, but what?

you would need to define it in your data section:

then do this

Thanks madmatt it worked .