iTween onstartparams

Could anyone help me to get this to work, please?:

function SomeFunction()
{
    iTween.MoveBy(go[i2],{"z":-5, "delay":t00 + t01 + i2*del2,"onstart":"activate", "onstartparams":"go[i2]"});
}

function activate (g: GameObject) {
    Debug.Log("n2 "+ g.name);
    g.renderer.enabled = true;
}

I have edited your question. Each parameters for iTween must be arranged that way : [name of the parameter as a string], [value]. I replaced ‘:’ by ‘,’.