PLotting the Hyper plane throgh [a,b,c] with offset [a0,b0,c0]

Hi all,
I am using SVM to classify 3d data. I tried SVM in 2d case and it worked.I am new to Matlab. I have obtained Weight vector and Offset vector. Here I have two questions.

1. Does the Offset in case of 3d would be 3dimensional or 2 dimensional because in 2d case its one dimensional

2. Secondly, If I get the weight vector(w=[a,b,c,d]) and Offset(say w0). Hw can I plot the Decision Hyperplane(since its 3d I call it a plane) through Matlab.

Kindly help me,

Thanks,
Pavan.