link 8, introduced tensile curve and compression curve

Hi.

I'm working  with the element link8 (Ansys 12.1) and I have to introduced the tensile curve and compression curve, but I don't know, How I have to introduced its???

I have worked with the comands: TB: aniso, miso,..., I think the best option is: TB, user, but How I have to introduced the values of tensile and compression curve?, when this are different.

 File attachment is the tensile and compression curve to introduce

Thank you, Toni