Distance between point and line

Hi,

I want to find the distance between a point and a line, but using projections. I get an answer of $\displaystyle root(10)$ but I'm pretty sure that this is not the right answer.

My point is

P = (2,-1,-1)

and the line is given by vector form

L: (1,0,01) + t(1,2,1) , t E R

I understand that w2 = $\displaystyle \vec{v}$ - w1

I think that I have a point Po=(1,0,-1) and that I can say that $\displaystyle \vec{u}=(1,2,1)$ .... but I'm not sure at all about that.

Anyone can help me ?