Having wrong texture on my model?

I wanna change material of object programmatically, i am using this code, and have assigned both variables in inspector view but when i run the program it show just pink texture on my object. here is my code and screen shot. please help and thanks in advance.

#pragma strict

 var yourMaterial : Material;
 var newMaterial : Material;

function Start () {
    renderer.material = yourMaterial;
}

[30722-screen+shot+2014-08-11+at+12.50.22+pm.png|30722]

the inspector shows that there are no materials assigned to yourMaterial or newMaterial - that’s why it shows up pink.